Okay, first you need to understand that function of x, (or f(x)) is y.
We now plug in x.
f(-2) or y=-2(3)+(2•2)+4(-2)+8
f(-2)=-6+4+-8+8
f(-2)=-2
When x=-2, y=-2. Lets plug it back in to see if its true.
-2=-2(3) + (2x2) + (4(-2)) + 8
-2 = -6 + 4 + -8 + 8
-2 = -2.
Heart if it helps, comment if you need help.
