[tex]$f(x) = 5x + 3$[/tex]. Find the inverse of [tex]$f(x)$[/tex].

A. [tex]$f^{-1}(x) = 3 - 5x$[/tex]

B. [tex]$f^{-1}(x) = \frac{x - 3}{5}$[/tex]

C. [tex]$f^{-1}(x) = 5x - 3$[/tex]

D. [tex]$f^{-1}(x) = \frac{x - 5}{3}$[/tex]



Answer :

To find the inverse of the function [tex]\( f(x) = 5x + 3 \)[/tex], we need to follow these steps:

1. Replace [tex]\( f(x) \)[/tex] with [tex]\( y \)[/tex]:
[tex]\[ y = 5x + 3 \][/tex]

2. Swap [tex]\( x \)[/tex] and [tex]\( y \)[/tex] to find the inverse function:
[tex]\[ x = 5y + 3 \][/tex]

3. Solve for [tex]\( y \)[/tex]:
[tex]\[ x = 5y + 3 \][/tex]
Subtract 3 from both sides:
[tex]\[ x - 3 = 5y \][/tex]
Divide by 5:
[tex]\[ y = \frac{x - 3}{5} \][/tex]

Thus, the inverse function is:
[tex]\[ f^{-1}(x) = \frac{x - 3}{5} \][/tex]

Now, compare this result with the given options:

A. [tex]\( f^{-1}(x) = 3 - 5x \)[/tex]

B. [tex]\( f^{-1}(x) = \frac{x - 3}{5} \)[/tex]

C. [tex]\( f^{-1}(x) = 5 x - 3 \)[/tex]

D. [tex]\( f^{-1}(x) = \frac{x - 5}{3} \)[/tex]

The correct option is [tex]\( \boxed{B} \)[/tex].