Question

-2x-2y=-8
-4x-8y=-20

Answer 1

-2x-2y=-8

-4x-8y=-20

From the 1st eqn

Dividing through by 2

you have

-x-y=-4

Multiply through by -(minus)

x+y=4

x=4-y

Substitute into eqn 2

-4x-8y=-20

-4(4-y)-8y=-20

-16 + 4y - 8y = -20

-4y = -20 +16

-4y = -4

y= 1

Substitute into any of the other eqn's to get x

x= 4-y

x= 4-1

x=3