Question

f (x) = 2x2 + 3x + 48(x) = x + 5What is (f (x)) . (g(x))?A. 2x2 + 4x + 9B. 2x2 + 23x + 69C. 2x3 + 3x2 + 4x + 20D. 2x3 + 13x2 + 19x + 20

Answer 1

We have the functions:

$\begin{gathered} f(x)=2x^2+3x+4 \\ g(x)=x+5 \end{gathered}$

Then their multiplication is:

$\begin{gathered} f(x)\cdot g(x)=(2x^2+3x+4)(x+5) \\ =2x^3+10x^2+3x^2+15x+4x+20 \\ =2x^3+13x^2+19x+20 \end{gathered}$

Therefore:

$f(x)\cdot g(x)=2x^3+13x^2+19x+20$

and the answer is D.