x - 3x - 4 if x =-2

Answer 1

(-2) - 3(-2) - 4 = -2+6-4 = 0
or
-x-3x-4 = -2x-4 = -2(-2)-4 = 4-4 = 0
or maybe you meant
x^2 - 3x - 4 = (-2)^2 - 3(-2) - 4 = 4+6-4 = 6