-5y + 9x=27

8y - x=-70

First find opposites.

You can do this by multiplying the second equation by 9 getting

72y - 9x = -630

Now add this to the first equation. (Add the y terms together, the x terms together and the constants together. You should find the x terms cancel each other out.)

-5y + 9x=27

72y - 9x = -630

67y = -603

y = -9

Now that you know the value of y, plug the value into both equations...hopefully getting the same answer.

-5(-9) + 9x = 27 8(-9) -x = -70

45 + 9x = 27 -72 - x = -70

9x = -18 - x = 2

x = -2 x = -2

Your point of intersection is (-2, -9). This is also your solution to the system.

## We’ll help your grades soar

Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.

- 30,000+ book summaries
- 20% study tools discount
- Ad-free content
- PDF downloads
- 300,000+ answers
- 5-star customer support

Already a member? Log in here.

Are you a teacher? Sign up now