Question

Which function is the inverse of f(x) = –5x – 4?

Answer 1

Answer:

$f^{-1}(x)=-\frac{1}{5}x-\frac{4}{5}$

Step-by-step explanation:

we have

$f(x)=-5x-4$

Let

$y=f(x)$

$y=-5x-4$

Step 1

Exchange the variables x for y and y for x

$x=-5y-4$

Step 2

Isolate the variable y

$x=-5y-4$

$5y=-x-4$

$y=-\frac{1}{5}x-\frac{4}{5}$

Step 3

Let

$f^{-1}(x)=y$

$f^{-1}(x)=-\frac{1}{5}x-\frac{4}{5}$

Answer 2

Just took the test. A is the right answer.