Question

If f(x) = -5x -9 then f^-1(x) = ____

Answer 1

f⁻¹(x) = -(x+9) / 5

Explanation:

We have given a function.

f(x) = -5x -9

We have to find inverse of given function.

Let y = f(x)

y = -5x-9

Solving above equation for x, we have

x = -(y+9) / 5

Putting x = f⁻¹(y) in above equation ,we have

f⁻¹(y) = -(y+9) / 5

Replacing y by x, we have

f⁻¹(x) = -(x+9) / 5 which is the answer.

Answer 2

`f^(-1)(x)=-(x+9)/(5)`;

Explanation:

The given linear function is;

`f(x)=-5x-9`

Let
`y=-5x-9`;

Interchange
`x` and
`y` to get;

`x=-5y-9`;

Solve for
`y`.

`x+9=-5y`

Divide both sides by -5

`(x+9)/(-5)=y`;

This implies that;

`f^(-1)(x)=-(x+9)/(5)`;