#### Answer

$(5g-1)(4g^2-5)$

#### Work Step by Step

Using factoring by grouping, the factored form of the given expression, $
20g^3+5-4g^2-25g
,$ is
\begin{array}{l}
20g^3-4g^2-25g+5
\\\\=
(20g^3-4g^2)-(25g-5)
\\\\=
4g^2(5g-1)-5(5g-1)
\\\\=
(5g-1)(4g^2-5)
.\end{array}