Question

Express your answer as a polynomial in standard form.9f(x) = x2 - 4x –g(x) = -3x – 5Find: f(g(x))

Answer 1

Given the functions:

`\begin{gathered} f(x)=x^2-4x-9 \\ g(x)=-3x-5 \end{gathered}`

We need to find the function f(g(x)

So, every variable for x in the function f(x) will be substituted with g(x) as follows:

`f(g(x))=(-3x-5)^2-4\cdot(-3x-5)-9`

Now, we will simplify the expression:

`\begin{gathered} f(g(x))=9x^2+30x+25+12x+20+9 \\ \\ f(g(x))=9x^2+42x+54 \end{gathered}`

So, the answer will be:

`f(g(x))=9x^2+42x+54`