Question

If f(x) and f^-1(x) are inverse functions of eachother and f(x)=2x+5, what is f^-1(8)

Answer 1

1.5

Explanation:

The value of x such that f(x) = 8 is ...

8 = 2x +5

3 = 2x

1.5 = x

f^-1(8) = 1.5