51.5k views
4 votes
NEED HELP ASAP!!! 20 POINTS

Solve using Elimination:


7x + 2y = 24


4x + y = 15


Solution = ( , )

1 Answer

2 votes

Answer:

(6, -9)

Explanation:

Eliminate y (you can do x too, but y is easier for this problem)

To eliminate y we must get 0y

If one is 2y, the other must be -2y to get to 0

Keep the first equation the same

7x + 2y = 24

Multiply all numbers in the second equation by -2 (so y can be -2y)

-8x + -2y = -30

Positive + Negative = Negative

-8x - 2y = -30

Now add/subtract the two equations from each other

7x + 2y = 24

-8x - 2y = -30

-1x + 0y = -6

-1x = -6

Divide both sides by -1 to isolate variable

-1x ÷ -1 = -6 ÷ -1

x = 6

We could simply plug in the x value into one of the equations, but that's substitution - not elimination. Repeat the same steps for x

I will multiply the first equation by 4 to get 28x and the second equation by -7 to get -28x for an answer of 0x

28x + 8y = 96

-28x - 7y = -105

0x + 1y = -9

1y = -9

Divide both sides by 1 to isolate the variable

1y ÷ 1 = -9 ÷ 1

y = -9

User Yarelis
by
9.0k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories