Chapter 5 - Polynomials and Factoring - 5.1 Introduction to Factoring - 5.1 Exercise Set - Page 311: 62

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

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}