Question

8. Use the pair of functions to find the value of each of the following combination of functions.

Answer 1

The given functions are

$f(x)=x^2,g(x)=\frac{25}{-8x-1}$

We need to find

$(f+g)(9)$

That means we will add f and g, then substitute x by 9

$(f+g)(x)=x^2+\frac{25}{-8x-1}$

Substitute x by 9

$(f+g)(9)=9^2+\frac{25}{-8(9)-1}$

Simplify it and solve

$\begin{gathered} (f+g)(9)=81+\frac{25}{-72-1} \\ \\ (f+g)(9)=81-\frac{25}{73} \\ \\ (f+g)(9)=80\frac{48}{73} \end{gathered}$

The answer is (f + g)(9) = 80 48/73