Chapter 5 - Polynomials and Factoring - 5.3 Factoring Trinomials of the Type ax2+bx+c - 5.3 Exercise Set: 44

$(7t-8)(5t+3)$

Grouping the first and second terms and the third and fourth terms, the given expression is equivalent to \begin{array}{l}\require{cancel} 35t^2-40t+21t-24 \\\\= (35t^2-40t)+(21t-24) .\end{array} Factoring the $GCF$ in each group results to \begin{array}{l}\require{cancel} 5t(7t-8)+3(7t-8) .\end{array} Factoring the $GCF= (7t-8) $ of the entire expression above results to \begin{array}{l}\require{cancel} (7t-8)(5t+3) .\end{array}