Question

Given that f(x) = x2 –3x – 40 and g(x) = x +5, find (f +g)(x) and express

the result in standard form.

Answer 1

`(f+g)(x)=x^2-2x-35`

Explanation:

So we have the two functions:

`f(x)=x^2-3x-40\text{ and } g(x)=x+5`

And we want to find (f+g)(x). This is the same as:

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

Substitute:

`=(x^2-3x-40)+(x+5)`

Combine like terms:

`=x^2+(-3x+x)+(-40+5)`

Add:

`=x^2-2x-35`

And we're done!