How do you solve the system of equations 2y = 10-7x and 2x=20-2y?

1 Answer
Nov 8, 2017

Solve for x, then y using elimination.

x = -2, y = 12

Explanation:

First, move x and y to the same side of the equation so they are on top of each other. Make sure to watch your signs. Add 7x to the top and add 2y to the bottom.

7x + 2y = 10
2x + 2y= 20

Multiply bottom equation by -1 to eliminate y.

7x + 2y = 10
-2x - 2y = -20

Add the bottom equation to the top. You're left with only x.

5x = -10

Solve for x, then plug x into either of the original equations to get y.

x = -2, y = 12