52.2k views
1 vote
Solve this system of linear equations. Separate the x- and y-values with a comma. -7x + 2y = -8 -16x + 9y = 26

1 Answer

3 votes
(4,10).
1. There are three ways to solve this: elimination, substitution, graphing.
2. I chose elimination, so I had to get one negative variable and one positive variable of the same value (for example, 18 and -18)

-7x+2y=-8
-16x+9y=26
I chose to get 2y and 9y to equal -18y and 18y.
So, multiply the first equation by -9. Multiply the second by 2.
63x-18y=72
-32x+18y=52
the 18s cross each other out. So you're left with
63x=72
-32x=52. Add them.
31x=124, divide both sides by 31, and you'll get 4.
x=4
Plug your answer for x into one of the equations. Let's use the first one.
-7(4)+2y=-8
-28+2y=-8. add 28 to both sides.
2y=20, divide both sides by 2.
y=10.
This makes your answer (4,10)
User Bastian Stein
by
9.1k points

No related questions found

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