Question

If f(x) = 8x + 16, then find f -1(x).

Answer 1

Rewrite

−

1

x

as

−

x

.

f

−

x

Answer 2

The inverse is (x-16)/8

Explanation:

To find the inverse, exchange x and y and then solve for y

y = 8x +16

Exchange x and y

x = 8y +16

Solve for y

Subtract -16

x-16= 8y +16-16

x-16 = 8y

Divide by 8

(x-16)/8 = 8y/8

(x-16)/8 = y

The inverse is (x-16)/8