ANSWER
x = -2, y = -18
x = -3, y = -21
x = 4, y = 0
Step-by-step explanation
We want to find y for
f(x) = 3x - 12
when x = -2, -3 and 4
y and f(x) represent the same thing, so we have to just find f(x).
WHEN x = -2:
f(x) = 3(-2) - 12
f(x) = -6 - 12
f(x) = -18
WHEN x = -3:
f(x) = 3(-3) - 12
f(x) = -9 - 12
f(x) = -21
WHEN x = -4:
f(x) = 3(4) - 12
f(x) = 12 - 12
f(x) = 0