Question

If f(x) = x2 - 2x and g(x) = 6x + 4 for which value of x does (t +g)(x)=0​

Answer 1

-2

Assumption:

Find the value of x such that
`(f+g)(x)=0`.

Explanation:

`(f+g)(x)=0`

`f(x)+g(x)=0`

`(x^2-2x)+(6x+4)=0`

Combine like terms:

`x^2+4x+4=0`

This is not too bad too factor on the left hand side since 2(2)=4 and 2+2=4.

`(x+2)(x+2)=0`

`(x+2)^2=0`

So we need to solve:

`x+2=0`

Subtract 2 on both sides:

`x=-2`

Let's check:

`(f+g)(-2)`

`f(-2)+g(-2)`

`((-2)^2-2(-2))+(6(-2)+4)`

`(4+4)+(-12+4)`

`(8)+(-8)`

`0`

0 was the desired output of
`(f+g)(x)`.