X-2y=-2
y=2x+4

solve by substitution

Subsitut 2x+4 for y

x-2(2x+4)=-2
x-4x-8=-2
-3x-8=-2
add 8 to both sides
-3x=6
divide by -3
x=-2
sub back

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

x=-2
y=0
(x,y)
(-2,0)

10.4 is the answer for you