Question

A function is given.

f(x) = 4x – 8
What is the input of the function when the output is 20?
I

Answer 1

Given:

The function is

`f(x)=4x-8`

To find:

The input of the function when the output is 20.

Solution:

We have,

`f(x)=4x-8`

Here, x is input and f(x) is output.

Put f(x)=20 in the given function to find the input of the function when the output is 20.

`20=4x-8`

`20+8=4x`

`28=4x`

Divide both sides by 4.

`(28)/(4)=x`

`7=x`

Therefore, the required input value is 7.