Answer
$(4x+3)(5x+2)$
Work Step by Step
The two numbers whose product is $
20(6)=120
$ and whose sum is $
23
$ are $\{
15,8
\}$. Using these numbers to decompose the middle term of the trinomial results to
\begin{array}{l}
20x^2+23x+6
\\=
20x^2+15x+8x+6
\\=
(20x^2+15x)+(8x+6)
\\=
5x(4x+3)+2(4x+3)
\\=
(4x+3)(5x+2)
.\end{array}
