X+2y=4

-x-2y=-4

the solutions

subtract equations to form the equation of:

2x + 2y = 8

rearrange first equation to make x the subject:

x = 4 - 2y

subsitute into 2x + 2y = 8

2 (4 - 2y) + 2y = 8

8 - 4y + 2y = 8

collect like terns

-2y + 8 = 8

8s cancel out

-2y = 0

divide by - 2

y = 0

substitute y value into x + 2y = 4

x + 2 (0) = 4

solve for x

x + 0 = 4

x = 4

therefore, the solutions are:

x = - 4y = 0