Question

Solve the system by substitution.
y = x
y = 2x – 8

Answer 1

y=8

x=8

Explanation:

y=2y-8

-y=-8

y=8

x=8

Answer 2

x =y= 8

Explanation:

y = x

y = 2x – 8

Replace y with x

x = 2x-8

Subtract 2x from each side

x-2x = 2x-8-2x

-x = -8

Multiply each side by -1

x = 8

Now solve for y

y=x

y = 8