Question

F

(
x
)
=
4
x
+
3
,
what is the value of
f
(
3
)
?

Answer 1

21

Explanation:

If x was more than 1, then it would be impossible because fx would have to be even, but 4x+3 would be odd. Therefore, x must equal 1, and f must equal 7. This means that 3f=21