What is the inverse of the function below?

[tex]\[ f(x)=\frac{x}{5}-2 \][/tex]

A. [tex]\[ f^{-1}(x)=5(x-2) \][/tex]

B. [tex]\[ f^{-1}(x)=2(x+5) \][/tex]

C. [tex]\[ f^{-1}(x)=2(x-5) \][/tex]

D. [tex]\[ f^{-1}(x)=5(x+2) \][/tex]



Answer :

To find the inverse of the function [tex]\( f(x) = \frac{x}{5} - 2 \)[/tex], we follow these steps:

1. Replace [tex]\( f(x) \)[/tex] with [tex]\( y \)[/tex]:
[tex]\[ y = \frac{x}{5} - 2 \][/tex]

2. Swap [tex]\( x \)[/tex] and [tex]\( y \)[/tex]:
[tex]\[ x = \frac{y}{5} - 2 \][/tex]

3. Solve for [tex]\( y \)[/tex]:

- First, add 2 to both sides to isolate the fraction:
[tex]\[ x + 2 = \frac{y}{5} \][/tex]

- Next, multiply both sides by 5 to solve for [tex]\( y \)[/tex]:
[tex]\[ 5(x + 2) = y \][/tex]

Therefore, the inverse function is:
[tex]\[ f^{-1}(x) = 5(x + 2) \][/tex]

So, the correct option is:
D. [tex]\( f^{-1}(x) = 5(x + 2) \)[/tex]