Respuesta :

Polyblock

Answer:

x = 6

Step-by-step explanation:

y = -x - 4

3x + y = 8

Substitute the y with -x - 4

3x - x - 4 = 8

Combine the terms

2x - 4 = 8

Move the constant to the other side

2x - 4 = 8

    +4  +4

2x = 12

Divide both sides by 2

2x/2 = 12/2

x = 6