Question

If f(x) = 7x + 9x + 2, then f-1(x) = __________.f -1(x) = 16(x - 2)f -1(x) = (x - 2)/16f -1(x) = (1/16)(x + 2)f -1(x) = (1/8)(x - 2)

Answer 1

Solution

Given the function as shown below

$f(x)=7x+9x+2$

To find the inverse of f(x), we will set it to y first

$\begin{gathered} y=7x+9x+2 \\ y=16x+2 \end{gathered}$

Swap the position of y and x, then solve for y

$x=16y+2$$\begin{gathered} x-2=16y \\ \frac{x-2}{16}=y \\ f^{-1}(x)=y \\ f^{-1}(x)=\frac{x-2}{16} \end{gathered}$

Hence, the inverse of the function f(x) is:

$f^{-1}(x)=\frac{x-2}{16}$

Option B is the right choice