Question

For the function f(x) = 2 - 3x, find f(-4)

Answer 1

If you have f(x) = something, then f(a) will just have all the x values in f(x) replaced with a instead.
So in this situation, for 2-3x, replace x with -4, simplify it, and you have your answer

Answer 2

f(x)=2-3x
this is a function of x

if you want a function of -4, f(-4), then you will use -4 instead of x
f(x)=2-3(-4)

solve it