Question

Solve this question with the elimination method
X - 2y = 4
Y = x- 2

Answer 1

y = x - 2
-x + y = -2

-x + y = -2
x - 2y = 4
--------------add
-y = 2
y = -2

x - 2y = 4
x - 2(-2) = 4
x + 4 = 4
x = 4 - 4
x = 0

solution is (0,-2)

Answer 2

x - 2y = 4
y = x - 2

rewrite the second equation.
x - 2y = 4
-x + y = -2
------------------
       - y = 2
Divide both sides by - 1
y = -2

Plug -2 back in to either equation to solve for x.

- 2 = x - 2
add 2 to both sides.
0 = x
(0, -2)