Question

Use addition to solve the system of linear equations. Include all of your work in your final answer.
{-x- y = 4
{x + 2y = 4


WRITER

Answer 1

We are given
- x - y = 4
x + 2y = 4

Add the two equations to eliminate x:
(-x + x) + (-y + 2y) = 4 + 4
0 + y = 8
y = 8

Substitute y = 8 into x + 2y = 4:
x + 2(8) = 4
x + 16 = 4
x = 4 - 16 = -12

Check in the first equation: -(-12) - 8 = 12 - 8 = 4 ✓

Solution: (x, y) = (-12, 8).