Question

What is the inverse of the function below? f(x) = 5x - 2

Answer 1

Answer:

B. f -1(x) = x + 2 / 5

$f^{-1}(x)=\frac{x+2}{5}$

Step-by-step explanation:

To find the inverse of a function we need to interchange x and y an solve for y.

Since $f(x)=y$, then

$f(x)=5x-2$

$y=5x-2$

$x=5y-2$

Add 2 to both sides

$x+2=5y-2+2$

$x+2=5y$

Divide both sides by 5

$\frac{x+2}{5}=\frac{5y}{5}$

$\frac{x+2}{5}=y$

$y=\frac{x+2}{5}$

$f^{-1}(x)=\frac{x+2}{5}$

We can conclude that the correct answer is B. f -1(x) = x + 2 / 5