Solve
$x - 2y + 4 = 0$
$5x - 5y + 18 = 0$
x=−56/15,y=2/15 solve by subsitution
x - 2y + 4 = 0 rearrange as
x = 2y - 4 sub this into the second equation for x
5 ( 2y -4) + 5y + 18 = 0 simplify
10y - 20 + 5y + 18 = 0
15y - 2 = 0
15y = 2
y = 2 /15
So
x = 2(2/15) - 4 = 4/15 - 4 = 4/15 - 60/15 = -56 / 15
