PLEASE HELP NEED ASAP! 10 PTS!
Solve each system by elimination.
1. -9x+2y= -1.
18x-7y=17

2. 4x+18y= -28
2x+9y= -14

3. 20x+y= -11
-10x-3y= -17

4. -3x+y=7
-6x+2y=12

Thank you!

Answers

Answer 1
Problem 1
-9x + 2y = -1             (1)
18x - 7y = 17             (2)
To eliminate x, multiply (1) by 2 to obtain
-18x + 4y = -2
 18x - 7y = 17
Add the two equations.
-3y = 15
y = -5
From (2), obtain
18x = 17 + 7y = 17 + 7*(-5) = -18
x = -1

Answer:  x= -1, y = -5

Problem 2.
4x + 18y = -28           (1)
2x + 9y = -14             (2)
Divide (1) by 2 to obtain the system of equations
2x + 9y = -14
2x + 9y = -14
These two equations re identical.
Therefore there are an infinite number of solutions.

Answer:
There is no unique set of solutions.

Problem 3.
 20x + y = -11           (1)
-10x - 3y = -17         (2)
Multiply (2) by 2 to obtain
 20x + y = -11
-20x - 6y = -34
Add the two equations to eliminate x.
-5y = -45
y = 9
From (1), obtain
20x = -11 - y = -11 - 9 = -20
x = -1

Answer:  x = -1,  y = 9

Problem 4
-3x + y = 7           (1)
-6x + 2y = 12       (2)
Divide (2) to obtain the system of equations
-3x + y = 7
-3x + y = 6
Because 7 ≠ 6, th set of equations is nonsensical (inconsistent).

Answer:
The set of equations is invalid, and it has no solution.

Related Questions

The camera melissa wanted for her birthday is on sale at 27​%off the usual price. theamount of the discount is ​$99.90.what was the original price of the​ camera?​$nothing

Answers

divide the discount by the percentage off

 so:

99.90/0.27 = 370

 the original price was 370 dollars

Write the equation in standard form for the parabola with vertex (0,0) and directrix y=-6

Answers

Final answer:

To find the equation of a parabola with a vertex at (0,0) and a directrix of y=-6, we determine the focus is at (0,6), leading to the standard form equation of the parabola as y = 1/4x^2.

Explanation:

The question asks for the equation of a parabola in standard form given its vertex at (0,0) and directrix as y=-6. In parabolic equations, the standard form is usually y = ax^2 + bx + c for horizontal parabolas, or x = ay^2 + by + c for vertical parabolas. Given the vertex is at the origin (0,0) and the directrix is y = -6, this means the focus is at (0,6) because the distance from the vertex to the focus is equal to the distance from the vertex to the directrix but in the opposite direction.

For a parabola that opens upwards or downwards, the standard form is y = ax^2 (since the vertex is at the origin, b and c are 0). Given that the distance from the vertex to the focus (which is also the distance from the vertex to the directrix) is 6, the parabola opens upwards, and its focal distance (p) is 6. Hence, the value of 4p = 24, which leads us to conclude that a = 1/4. Therefore, the equation of the parabola is y = 1/4x^2.

a triangle has two sides of lengths 7 and 9.what value could the length of the third side be?

Answers

The side length has to be between 2 (=9-7) and 16 (=9+7). In both these corner cases the triangle will have collapsed to a line.

So the correct answers are B,C,D and E, and F is a corner case. Theoretically I suppose you have to count F in as a valid answer.

Answer:

13, 10, 8, 5

Step-by-step explanation:

2+7=9 9=9 the requirment is it has to be greater than the third length not equal to

You are taking a multiple-choice test that has 10 questions. each of the questions has four answer choices, with one correct answer per question. if you select one of these four choices for each question and leave nothing blank, in how many ways can you answer the questions?

Answers

1,048,576 or 4 to the tenth power

Show that the equation is not an identity by finding a value of x for which both sides are defined but not equal. cos x - cos x sinx = cos3 x

Answers

Answer:

The answer is pi/4

Step-by-step explanation:

You substitute each x for "pi/4", you will see that the equation is incorrect, the two values are no longer equal.

The equation is not an identity. Value of x = nπ, where n∈I , I → set of integers, for which both sides are defined but not equal.

What are the trigonometric identities?

Equations using trigonometric functions that hold true for all possible values of the variables are known as trigonometric identities.

We have the equation,

cos x - (cos x) (sin x) = cos³x

Simplifying,

cos x [ 1 - (sin x) ]  = cos²x (cos x)

1  - sinx = cos²x

1  - sinx = 1 - sin²x

1  - sinx = 1² - sin²x

1  - sinx = (1  - sinx)(1 +sinx)

1 = 1  + sinx

sinx = 0

x = nπ, where n∈I , I → set of integers.

It is not an identity equation.

cos x - (cos x) (sin x) ≠ cos³x

Therefore,  both sides are defined but not equal.

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If θ is in Quadrant III and cosθ -2/3, then sinθ = _____.


Answers

In 3rd quadrant, sine function is negative.
So, sin theta = sqrt(1-(2/3)^2) = - sqrt(5) / 3

Answer:

[tex]\sin\theta=-\dfrac{\sqrt{5}}{3}[/tex]

Step-by-step explanation:

If θ is in Quadrant III

[tex]\cos\theta=-\dfrac{2}{3}[/tex]

As we know in III quadrant cosine and sine both are negative.

using trigonometry identity

[tex]\sin\theta=-\sqrt{1-\cos^2\theta}[/tex]

[tex]\sin\theta=-\sqrt{1-(\frac{2}{3})^2}[/tex]

[tex]\sin\theta=-\sqrt{1-\frac{4}{9}}[/tex]

[tex]\sin\theta=-\dfrac{\sqrt{5}}{3}[/tex]

Hence, The value of [tex]\sin\theta=-\dfrac{\sqrt{5}}{3}[/tex]

2x^3y + 18xy - 10x^2y - 90y Part A: Rewrite the expression so that the GCF is factored completely. (3 points)

Answers

Final answer:

To factor 2x^3y + 18xy - 10x^2y - 90y, find the GCF of the terms, rewrite the expression, factor out the GCF from the terms inside the parentheses, and simplify the expression.

Explanation:

To factor the expression 2x^3y + 18xy - 10x^2y - 90y, we can begin by finding the greatest common factor (GCF) of the terms. The GCF of the coefficients is 2, and the GCF of the variables is y.

So, we can rewrite the expression as 2y(x^3 + 9x - 5x^2 - 45).

Next, we can factor out the GCF from the terms inside the parentheses. The GCF of x^3, 9x, -5x^2, and -45 is x. Factoring out x, we get x(x^2 + 9 - 5x - 45).

Finally, we simplify the expression inside the parentheses. Rearranging the terms, we have x(x^2 - 5x + 9 - 45). Combining like terms, we get x(x^2 - 5x - 36).

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Jacob and Isaiah are brothers. Their combined ages are 63. Jacob is 7 years older than Isaiah. How old are each of the boys?

Answers

There are two unknowns in this problem. To start, let's assign variables to each of them. Let x be the age of Jacob and y be the age of Isaiah. Then, we formulate equations based on the relationships stated.

x = 7 + y   --> eqn 1
x + y = 63  --> eqn 2

Substituting eqn 1 to eqn 2, then solve for x and y:

(7+y)+y = 63
7 + 2y = 63
2y = 63 - 7
2y = 56
y = 56/2
y = 28
x = 28 + 7 = 35

Therefore, Jacob is 35 years old, and Isaiah is 28 years old.

Final answer:

To solve this problem, set up a system of equations and solve for the variables. Isaiah is 28 years old and Jacob is 35 years old.

Explanation:

To solve this problem, we can set up a system of equations.

Let's say Isaiah's age is represented by x. Jacob's age is then represented by x + 7, since he is 7 years older than Isaiah.

We know that the sum of their ages is 63, so we can set up the equation: x + (x + 7) = 63.

Simplifying the equation gives us: 2x + 7 = 63.

Subtracting 7 from both sides of the equation gives us: 2x = 56.

Dividing both sides of the equation by 2 gives us: x = 28.

So, Isaiah is 28 years old, and Jacob is 28 + 7 = 35 years old.

HELP Please THANKS (;

Answers

2x+2(x-4)=16
2x+2x-8=16
4x-8=16
4x=24
x=6
y=6-4
y=2
Answer is C

If tan y = 3 over y and cos x = y over z what is the value of sin x??
A. sin x = 3/z
B. sin x = 3y
C. sin x = z/3
D. sin x = 3z

Answers

Answer: (A) sin x° = 3/z

Step-by-step explanation: i couldnt find it anywhere else but i figured it out and dont worry i got it right on the quiz

Someone help me please !

Answers

AE x BE = DE x CE

6x5 = 30

6 x DE = 30

DE = 30/6 =5

DC = DE +CE = 5+6 =11

Answer is C) 11

Guys help me out with this one plizz

Answers

Getting two 6's in four rolls can happen in 6 ways. 4C2 = 6

The probability of getting two 6's is 1/36. Therefore,

6 times 1/36 = 1/6 or 0.16666666...

 Converting to a percent to the nearest tenth is 16.7%


The sum of three consecutive odd integers is 207. What are the​ integers?

Answers

Hey!

It says that it is the sum of 3 consecutive odd integers right?

So then we give these numbers some variables to work with like so...

x = 1st number
x + 2 = 2nd number
x + 4 = 3rd number

now set all of them equal to 207

x + x + 2 + x + 4 = 207
3x + 6 = 207
3x = 201
x = 67                     x + 2 = 69                 x + 4 = 71



Why is 8.8 classified as a rational number?

Answers

A rational number can be expressed as the ratio of two integers.

[tex]\frac{a}{b}[/tex]

Where a and b are integers and b is not equal to 0.

The rational number 8.8 can be expressed as two integers. Like [tex]\frac{8.8}{1}[/tex]


Jess observed that 60% of the people at a mall on a particular day shopped for clothes. If 2500 people at the mall did not shop for clothes that day, the number of people who shopped for clothes that day was ______.

Answers

If 60% shop for clothes, 40% do not shop for clothes.

p(40/100)=2500

40p=250000

p=6250 total people shopping, then:

p(60/100) is the number of people who shopped for clothes, since p=6250

6250(60)/100

3750 people shopped for clothes that day.

Answer:

3750

Step-by-step explanation:

3750

Find the slope of the line on the graph. Write your answer as a fraction or a whole number, not a mixed number or decimal.

Answers

(-2,2) and (0,4)
slope = (4 - 2)/(0+2) = 2/2 = 1

answer
slope = 1

Answer: -3

Step-by-step explanation:

The points (1,1) (2,-2) plugged into slope formula m = y2 - y2/x2 - x1

-2 is y2

1 is y1

2 is x2

1 is x1

Subtract and simplify

8y - 1 = x 3x = 2y Solve the system of equations by substitution.

Answers

Solve for the first variable in one of the equations, then substitute the result into the other equation.
(1/11, 3/22)

the question is............

Answers

A(n,s)=(ns^2)/(4tan(180/n)), n=number of sides, s=side length

A(8,4.6)=(8*4.6^2)/(4tan22.5)

A(8,4.6)=42.32/tan22.5 m  (exact)

A(8, 4.6)≈102.17 m^2  (to nearest hundredth of a square meter)

a hot air balloon holds 3,249 cubic meters kf helium. the density of the helium is 0.1785 kilograms per cubic meter. how many kilograms of helium does the balloon contain, round to the nearest tenth of a kilogram?

Answers

TO determine the mass of the helium in the balloon, we make use of the density of the gas that is given in the problem and the volume of helium that is present. Density is a property of a material which describes the mass of a material per unit volume. By multiplying the volume to density, we get the mass of the helium gas in the balloon. We do as follows:

Mass = Density x Volume
Mass = 0.1785 kg / m^3 x 3249 m^3
Mass = 579.9465 kg

Therefore, the mass of helium gas in the hot air balloon would be about 579.9 kg.

What is the measure of an exterior angle of a regular 11-sided polygon?

Answers

360 divided by 11 = 32.72 recurring

The measure of an exterior angle of a regular 11-sided polygon is 32.73°.

The measure of an exterior angle of a regular 11-sided polygon can be calculated using the formula:

60° divided by the number of sides.

In this case, for an 11-sided polygon, each exterior angle would measure 360° / 11 = 32.73°.

If a cone and a sphere have the same radius and the same height what is the relationship among the volumes of the two shapes

Answers

V (cone) = πR².H/3

V (sphere) =(4/3).π.R³

Given: Same Radius and  cone a nd sphere same  H =2R. Replace H with 2R

V (cone) = πR².(2R)/3 = 2πR³/3

Then V (sphere)[ = (4/3).π.R³]= 2 V (cone) [ = 2πR³/3]

Answer:

the volume of the sphere will be 4 times the volume of the cone;

Step-by-step explanation:

The question is on volume comparison

Volume of a sphere=4/3 ×r³

Volume of a cone= /3×r²h

where r is the radius and h is the height

Apply the condition

If r=h=1 unit

Then volume of sphere will be= 4/3 × ×1³ = 4/3

And volume of the cone will be= /3 ×1²×1 =/3

We can see the volume of the sphere will be 4 times the volume of the cone;

4/3 = 4×/3

John's Coffee Shop makes a blend that is a mixture of two types of coffee. Type A coffee costs John $4.70 per pound, and type B coffee costs $5.90 per pound. This month, John made 181 pounds of the blend, for a total cost of $967.10 . How many pounds of type A coffee did he use?

Answers

A +B = 181

A=181-B

4.70A+5.90B= 967.10

4.70(181-B) +5.90B =967.10

850.70-4.70B+5.90B=967.10

850.70+1.2B =967.10

1.2B=116.40

B =116.40/1.2 = 97

A=181-97 = 84 pounds of type A coffee


Which expression is equivalent to (2x^2 + 4x – 7)(x – 3)?
A. x(2x^2 + 4x – 7) + 3(2x^2 + 4x – 7)
B. x(2x^2 + 4x – 7) – 3
C. –3x(2x^2 + 4x – 7)
D. (2x^2 + 4x – 7)(x) + (2x^2 + 4x – 7)(–3)

Answers

The expression (2x² + 4x – 7)(x – 3) is equivalent to the expression (2x² + 4x – 7)(x) + (2x² + 4x – 7)(–3) option (D) is correct.

What is an expression?

It is defined as the combination of constants and variables with mathematical operators.

We have an expression:

= (2x² + 4x – 7)(x – 3)

After using the distributive property:

= (2x² + 4x – 7)(x) + (2x² + 4x – 7)(–3)

Distributed the whole term (2x² + 4x – 7) with (x - 3)

Thus, the expression (2x² + 4x – 7)(x – 3) is equivalent to the expression (2x² + 4x – 7)(x) + (2x² + 4x – 7)(–3) option (D) is correct.

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A parent rewards a child with 50 cents for each correctly solved mathematics problem and fines the child 30 cents for each incorrectly solved problem. if the child nets $22.00 after 100 problems. how many problems were solved correctly?

Answers

x = correct answer

y = incorrect answer

0.50x-0.30(100-x)=22.00
0.50x-30.00+0.30x=22.00
0.80x=22.00+30.00
0.80x=52.00
x=52.00/0.80

x= 65

y=100-65 = 35

0.5x65 = 32.50

35*0.30=10.5

32.5-10.5 = 22

 there were 65 correct answers


Answer:

65 problems were solved correctly, 35 incorrecly.

Step-by-step explanation:

1. Data:

Total answers= 100

50 cent = $0.50 for each correct answer

-30 cent = -$0.30 for each incorrect answer

Net reward= $22.00

2. Define Variables:

x= Correct answers

y= Incorrect answers

3. Formulate the Equations

Total number of answers (Eq 1)

[tex]x+y=100\\y=100-x[/tex]

Net reward (Eq 2)

[tex]0.50*x-0.30*y=22.00[/tex]

4. Solve by replaccing the Eq 1 in Eq 2 as follows:

[tex]0.50*x-0.30*y=22.00\\0.50*x-0.30*(100-x)=22.00[/tex]

5. Apply distrivutive property and operate:

[tex]0.50x-(0.30*100)+(0.30*x)=22.00\\0.50x-30.00+0.30x=22.00[/tex]

6. Separate numbers and variables on each side of the equation and solve

[tex]0.50x+0.30x=22.00+30.00\\0.80x=52.00[/tex]

7. Solve x

[tex]x=\frac{52.00}{0.8} \\x=65[/tex]

Now you know that correct answers are equal to 65

8. Find Incorrect Answers with Eq 1.

[tex]y=100-x\\y=100-65\\y=35[/tex]

Now you know that incorrect answers are equal to 35

9. Answer

65 problems were solved correctly, 35 incorrecly.

A worker produced a total of 198 mousetraps during a 6 hour run with no rejects and no downtime. A report states that this worker produced at a rate of 2 mousetraps per minute. Based on the actual production, is the rate of 2 mousetraps per minute accurate?Exit Test

Answers

1 hr = 60 minutes....so 6 hrs = (6 * 60) = 360 minutes

198 / 360 = 0.55 mousetraps per minute

no, 2 mousetraps per minute is not accurate

Based on the actual production, the rate of 2 mousetraps per minute is not accurate.

What is Rate?

Rate of a quantity is the amount of that quantity with respect to some amount of another quantity.

If the quantity with respect to which the rate is measured is taken as single unit or one unit, then the rate is called unit rate.

Production of mousetraps by the worker in 6 hours = 198

Production of mousetraps by the worker in 1 hour = 198/6 = 33

That is, production of mousetraps by the worker in 60 minutes = 33

Production of mousetraps by the worker in 1 minute = 33/60 = 0.55

The worker produced mousetraps at a rate of 0.55 mousetraps per minute.

But the report states that this worker produced at a rate of 2 mousetraps per minute, which is not correct.

Hence the statement of report that the worker produced at a rate of 2 mousetraps per minute is not accurate, because he is only producing 0.55 mousetraps per minute.

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Jamie has invested $1500 in a savings account. Each month the account pays an interest of 3.8%. How much money will she have in her account 4 years later if she does not make any deposits or withdrawals (round to the nearest dollar)?
A) $1,257
B) $1,557
C) $1,559
D) $2,341

Answers

Use the formula I=PRT. P = Principal, R = Rate, and T= Time. In this case P = 1500, R = 3.8%, and T = 48 because 12 months in a year multiplied by 4 years. So at the end, I = 1500*3.8%*48. Then add the amount from the equation to her starting balance of 1500

Answer:

$4236.

Step-by-step explanation:

We have been given that Jamie has invested $1500 in a savings account. Each month the account pays an interest of 3.8%. We are asked to find the total amount Jamie will have in her account after 4 years.

We will use simple interest formula to solve our given problem.

[tex]A=P(1+rt)[/tex], where,

A = Final amount after t years,

P = Principal amount,

r = Interest rate in decimal form,

t = Number of years.

Let us convert our given rate in decimal form.

[tex]3.8\%=\frac{3.8}{100}=0.038[/tex]

Since the we have been given monthly interest rate, so we will convert the given rate to annual interest rate by multiplying 0.038 by 12.

Upon substituting our given values in above formula we will get,

[tex]A=\$1500(1+0.038*12*4)[/tex]  

[tex]A=\$1500(1+1.824)[/tex]

[tex]A=\$1500(2.824)[/tex]  

[tex]A=\$4236[/tex]  

Therefore, Jamie will have $4236 in her account after 4 years.

Stan and hilda can mow the lawn in 30 min if they work together. if hilda works twice as fast as stan, how long does it take stan to mow the lawn alone?

Answers

Total Time = (Worker 1 * Worker 2) / (Worker 1 + Worker 2)
30 = (X*.5X) / (x + .5X)
30 = .5 X^2 / 1.5X
45 X = .5 X^2
Dividing both sides by X
45 = .5 X
X = 90
Stan will take 90 ,minutes and Hilda can do it in 45 minutes.
We can check this by putting the numbers in the formula:
30 = (45 * 90) / (45 + 90)
30 = 4,050 / 135
4,050 = 4,050
Answer is correct.



Find the area of the square.

Answers

the equation for the area of a square is just one side times another side, and all sides are equal so the area is simply 4 x 4 = 16.
Here is the formula for calculating the area of any square: [tex]A = s^2[/tex]

Where s is the side length of the square.

[tex]A = 4^2[/tex]
A = 16

So, the area of the square is 16 square units.

Which of the following is a key property of the linear parent function
A it is in quadratic ll and lV
B is has a slope of 1
C it is a curved line
D it does not go through the origin

Answers

it is definitely the letter B because of the liner parent function

Answer:

The correct option is B.

Step-by-step explanation:

The equation of linear parent function is

[tex]y=x[/tex]

Key property of the linear parent function are:

1. It is in quadratic l and lII.

2. It has a slope of 1.

3. It is a straight line.

4. It passes through the origin.

The graph of parent function is shown below.

In the given options only the statement " It has a slope of 1" is true.

Therefore the correct option is B.

.........simplify 3^2*3^5

Answers

Using order of operations, we can see we should first solve for the exponents, and then multiply the exponent values by each other.


3²×[tex] 3^{5} [/tex]
9×243
2187

Another way to solve this is to add the exponents together and simply do [tex] 3^{7} [/tex]. We can only do that in this case, however, because the values are being multiplied by each other.

Either way we solve, we will get 2187 as our final answer.
Hello there!
[tex]#3^2 * 3^5# #(3*3) * (3*3*3*3*3)# #(3*3*3*3*3*3*3)# #3^7# = #2187# I hope I helped :)[/tex]
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