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 = -4
y = 0
