Answer
$(3a-4)(2a-1)$
Work Step by Step
Grouping the first and second terms and the third and fourth terms, the given expression is equivalent to
\begin{array}{l}\require{cancel}
6a^2-8a-3a+4
\\\\=
(6a^2-8a)-(3a-4)
.\end{array}
Factoring the $GCF$ in each group results to
\begin{array}{l}\require{cancel}
2a(3a-4)-(3a-4)
.\end{array}
Factoring the $GCF=
(3a-4)
$ of the entire expression above results to
\begin{array}{l}\require{cancel}
(3a-4)(2a-1)
.\end{array}