System of equations me just solve show if possible

Equation 1)  y = 18 - 3x
Equation 2)  -2x - 4y = 8

Rearrange equation 1.

1)  3x + y = 18
2)  -2x - 4y = 8

Multiply equation 1 by 4.

1)  4(3x + y = 18)

1)  12x + 4y = 72
2)  -2x - 4y = 8

Add equations together.

10x = 80

x = 10

Plug in 10 for x in first equation.

y = 18 - 3x

y = 18 - 3(10)

Simplify.

y = 18 - 30

y = -12

(10, -12)

~Hope I helped!~