Determine the best method to solve the system of equations. Then solve the system.
-5x + 3y = -18
2x + 2y =4

Answers

Answer 1

Answer:

x=3

Step-by-step explanation:

Answer 2

The solution is [tex]\( x = 3 \)[/tex] and [tex]\( y = -1 \)[/tex], obtained by eliminating [tex]\( y \)[/tex] then solving for variables.

To solve the system of equations:

1. -5x + 3y = -18

2. 2x + 2y = 4

We can use either the substitution method or the elimination method. Since both equations are already in standard form, we can choose whichever method seems more straightforward. Let's start with the elimination method:

Elimination Method:

Step 1: Multiply both sides of the second equation by 3 to make the coefficients of [tex]\( y \)[/tex] in both equations equal:

Original equations:

1. -5x + 3y = -18

2. 2x + 2y = 4

Multiply the second equation by 3:

[tex]\[ 3(2x + 2y) = 3(4) \][/tex]

[tex]\[ 6x + 6y = 12 \][/tex]

Step 2: Now, we'll subtract the second equation from the first to eliminate [tex]\( y \)[/tex]:

[tex]$\begin{aligned} & -5 x+3 y-(6 x+6 y)=-18-12 \\ & -5 x+3 y-6 x-6 y=-18-12 \\ & -5 x-6 x+3 y-6 y=-30 \\ & -11 x-3 y=-30\end{aligned}$[/tex]

Step 3: Now, we have one equation with one variable:

[tex]\[ -11x - 3y = -30 \][/tex]

Step 4: Solve for [tex]\( x \)[/tex]:

[tex]$\begin{aligned} & -11 x=-30+3 y \\ & -11 x=3 y-30 \\ & x=\frac{3 y-30}{-11}\end{aligned}$[/tex]

Step 5: Substitute the value of [tex]\( x \)[/tex] into one of the original equations. Let's use the first equation:

[tex]\[ -5\left(\frac{3y - 30}{-11}\right) + 3y = -18 \][/tex]

Step 6: Solve for [tex]\( y \)[/tex]:

[tex]\[ \frac{15y - 150}{11} + 3y = -18 \][/tex]

[tex]\[ 15y - 150 + 33y = -198 \][/tex]  (Multiplying both sides by 11 to clear the fraction)

[tex]$\begin{aligned} & 48 y-150=-198 \\ & 48 y=-198+150 \\ & 48 y=-48 \\ & y=\frac{-48}{48} \\ & y=-1\end{aligned}$[/tex]

Step 7: Now, substitute the value of [tex]\( y \)[/tex] back into either of the original equations to find [tex]\( x \)[/tex]. Let's use the first equation:

[tex]$\begin{aligned} & -5 x+3(-1)=-18 \\ & -5 x-3=-18 \\ & -5 x=-18+3 \\ & -5 x=-15 \\ & x=\frac{-15}{-5} \\ & x=3\end{aligned}$[/tex]

So, the solution to the system of equations is [tex]\( x = 3 \)[/tex] and [tex]\( y = -1 \)[/tex].


Related Questions

Solve the equation by graphing.

m^2 + 2m =3

Answers

Answer:

Step-by-step explanation:

The following figures are not drawn to scale but AB and CD are straight lines. Find x

Answers

Answer:

x=45

Step-by-step explanation:

Since AB is a straight line, it is 180 degrees

AOE + EOF + FOD + DOB = 180

15+x+2x+120-2x = 180

Combine like terms

135 +x = 180

Subtract 135 from each side

135-135 +x = 180 -135

x = 45

Final answer:

To find x, use the concept of similar triangles and set up a proportion. Cross multiply and simplify the equation to solve for x.

Explanation:

To find x, we need to use trigonometry. Given that AB and CD are straight lines and the figures are not to scale, we can use the concept of similar triangles. We need to find the relationship between the corresponding sides of the triangles to find x.

Let's assume that the length of AB is a and the length of CD is b. From the given information, we can form a proportion:

a/b = (a+x)/a

Cross multiplying and simplifying the equation, we get:

a^2 = b(a+x)

Now we can substitute the given values to solve for x.

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The revenue each season from tickets at the theme part is represented by t(x) = 3x. The cost to pay the employees each season is represented by r(x) = (1.25)x. Examine the graph of the combined function for total profit and estimate the profit after five seasons.

Answers

Answer:

240

Step-by-step explanation:

Profit = revenue - cost

p(x) = 3^x - 1.25^x

       

5 seasons would be x = 5

p(5) = 3^5-1.25^5

p(5) = 239.948

It would be around 240

Answer: The profit after 5 seasons is $239.94.

Step-by-step explanation:

Since we have given that

Revenue function is given by

[tex]t(x)=3^x[/tex]

Cost function is given by

[tex]r(x)=1.25^x[/tex]

So, We need to find the total profit:

As we know the formula for profit:

Profit = Revenue - Cost

[tex]P(x)=t(x)-r(x)\\\\P(x)=3^x-1.25^x[/tex]

We need to evaluate the profit after five seasons:

[tex]P(5)=3^5-1.25^5\\\\P(5)=\$239.94[/tex]

Hence, the profit after 5 seasons is $239.94.

The rectangle has one side 8 cm and a diagonal that is 4 cm longer than the unknown side. Write an equation to solve for the missing side. What is the length of the diagonal?

Answers

Answer:

Step-by-step explanation:

you will have to divide them then you will be able to find the missing side

Use the image below and find x and y so that the quadrilateral is a parallelogram.
∠A=54, ∠B=12x+6, ∠C=6x+66, and ∠D=3y

Answers

Answer:

(x, y) = (10, 18)

Step-by-step explanation:

In a parallelogram, adjacent angles are supplementary, and opposite angles are congruent.

∠A = ∠D

54 = 3y

18 = y . . . . . divide by 3

___

∠B = ∠C

12x +6 = 6x +66

6x = 60 . . . . . . . . . subtract 6x+6

x = 10 . . . . . divide by 6

The values of x and y are 10 and 18, respectively.

Need help with a math question PLEASE HELP

Answers

Answer:

(-1, -3)

Step-by-step explanation:

We suppose your notation means you want to reflect given point P across the horizontal line y=1.

The x-coordinate will remain the same.

The new y-coordinate will be such that y=1 is the midpoint between the original and its reflection:

(5 + y)/2 = 1

5 + y = 2 . . . . multiply by 2

y = 2 -5 = -3 . . . subtract 5

The reflected point is (-1, -3).

___

The same sort of math applies whenever you have a midpoint and want to find the other end point. Double the midpoint value and subtract the end point you have in order to find the other end point.

What are the minimum, first quartile, median, third quartile and maximum of the data set 3,5,7,8,12,13,14,18,21

Answers

Answer:

3, 7, 12, 14, 21

Step-by-step explanation:

3 is the minimum value of the data set.

The median is 12. (it is in the middle of 3 and 12 if you look at the question)

The first quartile is 7 (if you count, it is equidistant from either end)

the third quartile is 14. (it is in the middle of 12 and 21 if you look at the question)

21 is the maximum value of the data set.

Answer: 3 is minimum, 7 is first quartile, 12 is median, 14 is third quartile, and 21 is maximum.

Trace a pattern block divided into two equal parts and write a unit fraction to describe the area of each part

Answers

Answer:

1/2

Step-by-step explanation:

The unit fraction for an area (or anything, for that matter) divided into n equal parts is 1/n. For 2 equal parts, it is 1/2.

A paper company needs to ship paper to a large printing business. The paper will be shipped in small boxes and large boxes. Each small box of paper weighs 45 pounds and each large box of paper weighs 70 pounds. There were 6 more small boxes shipped than large boxes and the total weight of all boxes was 1305 pounds. Determine the number of small boxes shipped and the number of large boxes shipped.

Answers

Step-by-step explanation:

Let's say S is the number of small boxes and L is the number of large boxes.

There were 6 more small boxes than large boxes, so:

S = L + 6

Each small box weighs 45 pounds, and each large box weighs 70 pounds.  The total weight was 1305 pounds, so:

45S + 70L = 1305

We can now solve the system of equations.  Using substitution:

45(L + 6) + 70L = 1305

45L + 270 + 70L = 1305

115L = 1035

L = 9

S = 9 + 6

S = 15

There are 15 small boxes and 9 large boxes.

We are required to determine the number of small boxes shipped and the number of large boxes shipped.

let

x = number of small boxes shipped

y = number of large boxes shipped

Weight of small boxes = 45 pounds

Weight of large boxes = 70 pounds

Total weight of boxes = 1305 pounds

There were 6 more small boxes shipped than large boxes

x = y + 6 (1)

x = y + 6 (1)45x + 70y = 1305 (2)

substitute x = y + 6 into (2)

45x + 70y = 1305

45(y + 6) + 70y = 1305

45y + 270 + 70y = 1305

45y + 70y = 1305 - 270

115y = 1035

divide both sides by 115

y = 1035 / 115

y = 9

Recall,

x = y + 6

x = 9 + 6

x = 15

Therefore,

the number of small boxes shipped is 15 and the number of large boxes shipped is 9

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A hat is marked down 45% and its new price is $69. What was the original price rounded to the nearest cent?

Answers

The original price rounded to the nearest cent was; $106.95

What is the fundamental principle of multiplication?

Multiplication is the mathematical operation that is used to determine the product of two or more numbers. If an event can occur in m different ways and if following it, a second event can occur in n different ways, then the two events in succession can occur in m × n different ways.

We are given that hat is marked down 45% and its new price is $69.

45% = 0.45

Therefore, we have;

1.00 - 0.45 = 0.55

$69 x 0.55 = 37.95

Then the original price rounded to the nearest cent was;

$69 + 37.95 = $106.95

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Final answer:

To calculate the original price of the hat before a 45% discount resulted in a new price of $69, divide the new price by 0.55. This calculation gives an original price of approximately $125.45, which is the price before the markdown rounded to the nearest cent.

Explanation:

To determine the original price of the hat before the markdown, we start with the new price which is after a 45% reduction. Since 100% - 45% is 55%, the new price represents 55% of the original price. We use the equation new price = (original price) x (percentage after discount) to solve for the original price.

So we have $69 = (original price) x 0.55. To find the original price, we divide the new price by 0.55:

Original price = $69 / 0.55

Calculating this gives us an original price of approximately $125.45. However, we need to round to the nearest cent resulting in $125.45 as the original price of the hat.

Zack computes the perimeter of a rectangle by adding the length, L, and width, W, together, then doubling the sum. Rachel computes the perimeter by doubling the length and doubling the width and then adding the doubled amounts.


I'll mark the brainliest!

Answers

Answer:

Step-by-step explanation:

Part A: 2(L + W) = P

Part B: 2L + 2W = P

Part C: 2(10 + 5) = 30

Part D: 2(10) + 2(5) = 30

Part E: The reason both strategies work is because of the distributive property (attached)

Both Zack and Rachel's methods for computing the perimeter of a rectangle lead to the same formula: Perimeter = 2 * (Length + Width).

To find the perimeter of a rectangle using Zack's method, he first adds the length (L) and the width (W) together, obtaining the sum (L + W). Next, he doubles this sum by multiplying it by 2, giving him the perimeter of the rectangle.

Perimeter (Zack) = 2 * (L + W)

On the other hand, Rachel takes a slightly different approach. She doubles the length (2 * L) and doubles the width (2 * W) separately, getting two new values. Then, she adds these doubled amounts together, resulting in the perimeter of the rectangle.

Perimeter (Rachel) = 2 * L + 2 * W

Let's analyze the two methods and see if they yield the same result.

We can start by simplifying Rachel's method:

Perimeter (Rachel) = 2 * L + 2 * W

= 2 * (L + W)

Now we can see that both Zack and Rachel's methods end up with the same expression: 2 * (L + W). This means that, despite their different approaches, they arrive at the same formula for calculating the perimeter of a rectangle.

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2 _
3 --- + 2.3=
3


giving 25 points for the right answer asap

Answers

[tex]

3 \frac{2}{3} + 2.3 \\

\implies 3 \frac{2}{3} + \frac{23}{10} \\

\implies \frac{11}{3} + \frac{23}{10} \\

\implies \frac{110+69}{30}

\implies \frac{179}{30}[/tex]

For this case we must indicate the value of the following expression:

[tex]3 \frac {2} {3} +2.3[/tex]

We have the following mixed number:

[tex]3 \frac {2} {3} = \frac {3 * 3 + 2} {3} = \frac {9 + 2} {3} = \frac {11} {3} = 3.6667[/tex]

So, we have:

[tex]\frac {11} {3} + \frac {23} {10} = \frac {10 * 11 + 3 * 23} {30} = \frac {110 + 69} {30} = \frac {179} { 30}[/tex]

In mixed number we have:

[tex]5 \frac {29} {30}[/tex]

ANswer:

[tex]5 \frac {29} {30}[/tex]

Find the length of the side not given when c is the hypotenuse and a and b are the legs. a = 9 and c= 13

Answers

Answer:

  b = 2√22 ≈ 9.381

Step-by-step explanation:

The Pythagorean theorem tells you ...

  a^2 + b^2 = c^2

Filling in the given numbers, we can solve for b.

  9^2 +b^2 = 13^2

  b^2 = 169 -81 = 88

  b = 2√22 . . . . . . . . take the square root and simplify

Which is the side length of a cube with a surface-area-to-volume ratio of faction 1/2

Answers

Answer:

12

Step-by-step explanation:

For a cube of side length, L

The following formulas apply:

Area = 6L²

Volume = L³

Area / Volume = 6L² ÷ L³ = 6/L

Try L = 12

Area / Volume = 6/12 = 1/2

Hence 12 is the answer.

A toy factor paints all of its rubber balls with 2 coats of of latex for durability. How many square centimeters of latex are needed to cover a rubber ball with a circumference of 16π cm?

Answers

Answer:

1 coat: 256π cm² ≈ 804.25 cm²2 coats: 512π cm² ≈ 1608.50 cm²   (rounds to 1608 cm²)

Step-by-step explanation:

The radius of the ball is ...

  r = C/(2π) = (16π cm)/(2π) = 8 cm

The formula for the area of a sphere is ...

  A = 4πr²

Filling in the value of the radius, we find the area of the ball to be ...

  A = 4π(8 cm)² = 256π cm² ≈ 804.25 cm²

Then 256π or 804.25 is the number of square centimeters needed to cover the given ball with one coat of latex.

If the ball is only considered to be covered when it has two coats of latex, then twice that amount, 512π or 1608.50 square centimeters of latex are required.

Final answer:

The amount of latex needed to cover a rubber ball with two coats, when the circumference of the ball is 16π cm, is 512π cm².

Explanation:

To calculate the amount of latex needed to paint a rubber ball, we first need to calculate the surface area of the ball. The formula for the surface area of a sphere is 4πr², where r is the radius of the sphere. Given that the circumference of the sphere (rubber ball) is 16π cm, we can substitute this into the formula 2πr to find the radius, which equals 8 cm.

Substituting the radius into the surface area formula, we get 4π(8 cm)² = 4π(64 cm²) = 256π cm². This is the surface area for one layer of latex. But as the toy factory paints their balls with two coats of latex, we need to double this surface area, which gives us 512π cm² as the total area to be covered with latex.

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Josephine earned a 15% return on her investments last year. If the inflation rate that year was 4%, what is her real rate of return?



A. 4%


B. 11%


C.15%


D.19%

Answers

The answer will be c

Answer:

B. 11%

Step-by-step explanation:

Using the formula

Real rate of return = nominal rate - inflation rate

Note that the nominal rate of a business is the return on investment in a particular year.

Therefore if Josephine earned a 15% return on her investments last year, her nominal rate is also 15%

Since the inflation rate is 4%

Rate of return = 15%-4%

Rate of return = 11%

You have 1/4 of a tank of gas and 10 dollars in your wallet. Gas is $2.50/gallon and your car holds 13 gallons. Explain how you would find out how many total gallons you have in your car after you put $10 worth of gas.

Answers

1. Find how much gas can be obtained: $10 goes into $2.50 4 times, so you can get 4 gallons.

2. Find how much gas is in the car: 1/4 of the maximum 13 gallons is 3.25 gallons, so there is already 3.25 gallons in your car.

3. Find how many gallons you have total: 4 gallons + 3.25 gallons =

7.25 gallons

The total gallons you have in your car after you put $10 worth of gas is 7.25 gallons.

It is required to find out how many total gallons you have in your car after you put $10 worth of gas.

What is arithmetic?

Arithmetic is the branch of mathematics that deals with the study of numbers using various operations on them. Basic operations of math are addition, subtraction, multiplication and division. These operations are denoted by the given symbols.

Given:

Best way to start this is to figure out how much gas you can get for that $10.  

Since gas is $2.50/gallon and you buy $10 worth, that says you'll get 4 gallons of gas ($2.50 * 4 = $10).  Now figure out how many gallons you have left in your car.  If you car holds 13 gallons, 1/4 of that is 3.25 gallons. Add the 3.25 gallons left to the 4 gallons you bought and you get 7.25 gallons in your car.

Therefore, the total gallons you have in your car after you put $10 worth of gas is 7.25 gallons.

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Maleek rested a 15.5-foot ladder against a building. The base of the ladder is 8.2 feet from the building. How far up the building does the ladder reach?

To the nearest tenth of a foot, about how far up the building does the ladder reach?

Answers

Here is the set up:

Use a^2 + b^2 = c^2

Let c = length of ladder

Let b = distance of ladder's base from the building.

We must find a.

(a)^2 + (8.2)^2 = (15.5)^2

a^2 = (15.5)^2 - (8.2)^2

a^2 = 173.01

Take the square root on both sides.

sqrt{a^2} = sqrt{173.01}

a = 13.1533265754

We now round off to the nearest tenth of a foot.

a = 13.2 feet

Did you follow?

The distance between the point of the base of the building to the point where the ladder touches it for this case is 13.14 ft approx.

What is Pythagoras Theorem?

If ABC is a triangle with AC as the hypotenuse and angle B with 90 degrees then we have:

[tex]|AC|^2 = |AB|^2 + |BC|^2[/tex]

where |AB| = length of line segment AB. (AB and BC are rest of the two sides of that triangle ABC, AC being the hypotenuse).

Consider the diagram attached below.

We've got:

|AC| = length of the ladder = 15.5 ft|BC| = distance of base of ladder from the base of building = 8.2 ft|AB| = length we need

Usually buildings are vertical, so perpendicular to the ground.

Therefore, we can take ABC a right angled triangle, and therefore, use Pythagoras theorem here:

[tex]|AC|^2 = |AB|^2 + |BC|^2\\\\15.5^2 = |AB|^2 + 8.2^2\\|AB|^2= 240 - 67.24\\\\|AB| = \sqrt{172.76} \approx 13.14 \: \rm ft[/tex]

(took only positive root as length cannot be negative).

Thus, the distance between the point of the base of the building to the point where the ladder touches it for this case is 13.14 ft approx.

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HELP ME PLEASE ITS IMPORTANT !!!


Marge runs an ice cream parlor. Her speciality is triple chocolate sundaes.She can prepare 1 sundae every 2 minutes, and she earns $1.20 for each sundae she makes . If she just makes sundaes for a single shift of at most 4 hours and at least 2 hours , which function relates her earnings to the number of minutes she works?

Answers

Answer:

4 hours = 4(60)=240min

2 hours = 2(60)=120min

120<=x<=240

f(x)=1.20||x/2||

So your answer is :

F(X)=1.20||x/2||, if 120<= x<= 240

Simplify (x^4y)^3.

A. x4y3
B. x7y3
C. x12y3

Answers

The answer would be c

Answer:

The answer is C.

Step-by-step explanation:

[tex]{( {x}^{4} y)}^{3} = {x}^{4 \times 3} {y}^{3} = {x}^{12} {y}^{3} [/tex]

Choose an equivalent system of equations to the following system:

Fx + Gy = H
Qx + Ry = S

A.6Fx + Gy = 6H
Qx + 6Ry = S

B.6Fx + 6Gy = 6H
Qx + Ry = S

C.Fx + 6Gy = 6H
Qx + Ry = S

D.6Fx + 6Gy = 6H
Qx − Ry = S

Answers

Answer:

B.  6Fx + 6Gy = 6H

    Qx + Ry = S

Step-by-step explanation:

Equivalent equations can be created many ways. One of the simplest is to multiply both sides of the equation by the same number. In the answer above, the first equation has been multiplied by 6. Nothing has been done to the second equation.

_____

Comments on other choices

A: some terms have been multiplied by 6. This changes the equation(s) so they are no longer equivalent to the ones you started with.

B: the correct choice

C: see A.

D: the first equation has been multiplied by 6, so that is equivalent to the original. The second equation has the sign of one of the terms changed, so it is now a different equation.

Answer: B.  6Fx + 6Gy = 6H

                     Qx + Ry = S


*The sum of two numbers is 400. If the first number is decreased by 20% and the second number is decreased by 15%, then the sum would be 68 less. Find the numbers after the decrease.

Answers

Answer:

The two numbers are .8*160=128 and .85*240=204

Step-by-step explanation:

First sentence:                 x+y=400

Second sentence           .8x+.85y=400-68

Solve y in the first sentence:  y=400-x

Plug first into second:     .8x+.85(400-x)=332

Distribute:                        .8x+.85(400)-.85x=332

Combine like terms:        -.05x+.85(400)=332

Simplify(multiply):              -.05x+      340=332

Subtract 340 on both sides:    -.05x       =332-340

Simplify(subtract):                     -.05x        =-8

Divide both sides by -.05:              x        =-8/-.05

Simplify (division):                           x        = 160

So y=400-x=400-160=240

Answer:

128 and 204. your welcome.

Step-by-step explanation:

Let x = the first number

Let y = the second number

So we can set up two equations:

x+y = 400

.8x + .85y = 400-68

Use substitution:

y = 400 - x

.8x + (.85)*(400-x) = 332

.8x + 340 -.85x = 332

8 = .05x

x = 160

So that makes y = 240

We want the decreased values so:

160*.8 = 128

240*.85 = 204

So the answers are 128 and 204

Ezra has a square brick patio he wants to reduce the width by 6 feet and increase the length by 6 feet ​

Answers

Answer:

A. lw = (x+6)(x -6); 133 square feet

Step-by-step explanation:

If x is the original length (in feet), when the length is increased by 6 feet, it can be represented by (x+6).

If x is the original width, when it is decreased by 6 feet, it can be represented by (x-6).

The area is the product of length and width, so the new area is ...

lw = (x+6)(x-6)

___

Since the original side is 13 ft, the new length is 13+6 = 19 ft, and the new width is 13-6=7 ft. The area is ...

(19 ft)(7 ft) = 133 ft²

Final answer:

To find the new dimensions of the brick patio, subtract 6 feet from the width and add 6 feet to the length.

Explanation:Mathematics – Middle School

To find the new dimensions of Ezra's brick patio, we need to subtract 6 feet from the width and add 6 feet to the length. Let's say the original width of the square brick patio is x feet. The new width would be (x - 6) feet. Similarly, if the original length is y feet, the new length would be (y + 6) feet. Therefore, the new dimensions of the patio would be (x - 6) feet by (y + 6) feet.

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Gina would like to apply for a loan, but knows that her current debt-to-income (DTI) ratio will keep her from being approved. Her current monthly debt includes a rent payment of $950.00, a car payment of $238.00, a student loan payment of $149.00, and two credit cards with a combined minimum monthly payment of $78.00. The bank requires a DTI of 36% in order to approve Gina?s loan application. What would Gina's gross monthly income need to be to get approved for the loan?

Answers

Answer:

  $3930.56

Step-by-step explanation:

The sum of her required payments is ...

  $950 +238 +149 +78 = $1415

In order for that to be 36% of her income, she must have income that matches ...

  1415 = 0.36 × income . . . . . . . to solve, we divide this equation by 0.36

  1415/0.36 = income ≈ 3930.56

Gina's gross monthly income would need to be $3930.56 to get approved.

_____

Comment on this answer

Often the DTI calculation will include the proposed loan payment. If that is the case, we would need to know the amount of the payment on the loan Gina is applying for. That amount would be added to her existing debt before dividing by 0.36.

Out of 100 students sampled, 70 of them said that they hoped to get married someday. With 68% confidence, what is the approximate percentage of the students in the population who hope to get married someday?

Answers

Answer:

65.4% to 74.6%

Step-by-step explanation:

68% is approximately plus minus 1 standard deviations.

sigma=sqrt(n*p*(1-p))=sqrt(100*.7*.3)=4.58

so we're looking at  70+4.6 and 70-4.6.

Answer: [tex](65.4\%,\ 74.6\%)[/tex]

Step-by-step explanation:

Given : Out of 100 students sampled, 70 of them said that they hoped to get married someday.

i.e. Sample size : n= 100 and Sample proportion:[tex]\hat{p}=\dfrac{70}{100}=0.7[/tex]

Using standard normal table for z,

Critical z-value(two-tailed) for 68% confidence = [tex]z_{\alpha/2}=0.9945[/tex]

Now, confidence interval for population proportion:-

[tex]\hat{p}\pm z_{\alpha/2}\sqrt{\dfrac{\hat{p}(1-\hat{p})}{n}}\\\\=0.7\pm(0.9945)\sqrt{\dfrac{(0.7)(0.3)}{100}}\\\\=0.7\pm0.0455737152863\\\\\approx0.7\pm0.046\\\\=(0.7-0.046,\ 0.7+0.046)=(0.654,\ 0.746)\\\\=(65.4\%,\ 74.6\%)[/tex]

Hence, the approximate percentage of the students in the population who hope to get married someday = [tex](65.4\%,\ 74.6\%)[/tex]

Perform the following division: (–1/6) ÷ (–3/7) A. –7/18 B. 7/18 C. –3/42 D. 3/42

Answers

Answer:

B. 7/18

Step-by-step explanation:

(-1/6)/(-3/7)

= -1/6 * -7/3

= -1*-7/6*3

= 7/18

(pls give brainliest)

For this case we must find the quotient of the following expression:

[tex]\frac {\frac {-1} {6}} {\frac {-3} {7}} =[/tex]

Applying double C we have:

[tex]\frac {-1 * 7} {6 * -3} =[/tex]

We have by law of signs of multiplication that:

[tex]- * + = -[/tex]

So:

[tex]\frac {-7} {- 18} =\\\frac {7} {18}[/tex]

Answer:

Option B

. The child’s physical density is being measured by the displacement method. A child of 50 pounds is placed in a tub filled with water, and the water that comes out of the tub goes into another small tub that measures 40 cm long, 30 cm wide, and 60 cm deep. The water level in the small tub is 18 cm high. Find the density of a child in gm/cm3 to the nearest hundredth. (Hint: density = mass/volume; 1 pound = 454 grams)

Answers

Answer:

  1.05 g/cm³

Step-by-step explanation:

The mass of the child is ...

  (50 lb)(454 g/lb) = 22,700 g

The volume displaced is ...

  (40 cm)(30 cm)(18 cm) = 21,600 cm³

Then the density of the child is ...

  mass/volume = 22700 g/(21600 cm³) ≈ 1.05 g/cm³

The point A (3, 4) is reflected over the line x = 2, and then is reflected over the line x = -4. What are the coordinates of A'? (1, 2) (9, 4) (-9, 4) (1, 4)

Answers

Answer:

The coordinates of A' are (-9,4)

Step-by-step explanation:

we know that

Each point of the original figure and its image are the same distance away from the line of reflection

so

step 1

reflected the point A(3,4) over the line x=2

The distance of the point to the line of reflection is 3-2=1 units

therefore

The coordinate of the reflected point is (2-1,4) ----> (1,4)

step 2

reflected the point (1,4) over the line x=-4

The distance of the point to the line of reflection is 1-(-4)=5 units

therefore

The coordinate of the reflected point is (-4-5,4) ----> (-9,4)

Answer: is c (-9,4) the guy had it right but wrong letter

Step-by-step explanation:

A particular bacteria population on an athlete's foot doubles every 3 days. Determine an expression for the number of bacteria N after T days, given the initial amount is 40 bacteria.​

Answers

Answer: [tex]\bold{N=40e^{\bigg(\dfrac{ln2}{3}\bigg)T}}[/tex]

Step-by-step explanation:

The exponential growth formula is:

[tex]A=Pe^{rt}\\\bullet A=final\ amount\\\bullet P=initial\ amount\\\bullet r=rate\ of\ growth\\\bullet t=time[/tex]

NOTE: This problem is asking to use N instead of A and T instead of t

Step 1: find the rate  

[tex]N=Pe^{rT}\\2P=Pe^{r\cdot 3}\quad \leftarrow(Initial\ population\ doubled\ N=2P, T=3\ days)\\2=e^{3r}\quad \qquad \leftarrow (divided\ both\ sides\ by\ P)\\ln\ 2=ln\ e^{3r}\quad \leftarrow(applied\ ln\ to\ both\ sides)\\ln\ 2=3r\quad \qquad \leftarrow (ln\ e\ cancelled\ out)\\\boxed{\dfrac{ln2}{3}=r}\quad \qquad \leftarrow (divided\ both\ sides\ by\ 3)[/tex]

Step 2: input the rate to find N

[tex]N=Pe^{rT}\\\\\bullet P=40\\\\\bullet r=\dfrac{ln2}{3}\\\qquad \implies \qquad \boxed{N=40e^{\bigg(\dfrac{ln2}{3}\bigg)T}}[/tex]

Answer:

[tex]\boxed{N = 40(2)^{\frac{T}{3}}}[/tex]

Step-by-step explanation:

The growth of bacteria is an exponential function. The equation has the general form

[tex]f(x) = ab^{x}[/tex]

Using the variables N and T, we can rewrite the equation as

[tex]N = ab^{T}[/tex]

We have two conditions:

(1) There are 40 bacteria at T = 0

(2) There are 80 bacteria at T = 3.

Insert these values into the equation.

[tex]\begin{array}{rrcll}(1)&40& = & a(b)^{0} & \\(2)&80 & = & a(b)^{3} & \\(3)& a & = & 40 & \text{Simplified (1)}\\ &80 & = & 40(b)^{3} & \text{Substituted (3) into (2)}\\ & b^{3} & = & 2 & \text{Divided each side by 40}\\ & b & = & (2)^{\frac{1}{3}} &\text{Took the cube root of each side}\\\end{array}\\\\\text{Thus, the explicit equation is } N = 40 \left (2^{\frac{1}{3}\right )^{T}}} \text{ or}\\\\\boxed{\mathbf{N = 40(2)^{\frac{T}{3}}}}[/tex]

a box without a top is made from a rectangular piece of cardboard with dimensions 12 cm by 10 cm, by cutting out square corners with side length x.

what x-value gives the greatest volume?
use technology to estimate your answer to the nearest tenth.

Answers

Answer:

  x ≈ 1.8 cm gives the greatest volume

Step-by-step explanation:

After cutting x cm from each corner in each direction, the cardboard can be folded up to make a box that is x cm deep and (12 -2x) by (10 -2x) in length and width. Clearly, values of x are limited to 5 or less, since cutting 5 cm from each side would leave a width of zero. Then the volume is given by ...

  V = x(12 -2x)(10 -2x)

The plot below shows the value of this cubic equation for volume, and identifies the peak as (x, V) ≈ (1.8, 96.8). That is, a cut of 1.8 cm will result in a box of approximate volume 96.8 cm³.

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