f(x)=|-3x-1|

Question

A) find f(-1)
B) find f(0)
C) find f(3)

Answer 1

x is just a place holder. You can replace it with any value.
f(-1) = |-3(-1)-1|
= |3-1| = |2| = 2
now do any other values you want

Answer 2

Thank you !