Answer
$(y+4)(2y-1)$
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}
2y^2+8y-y-4
\\\\=
(2y^2+8y)-(y+4)
.\end{array}
Factoring the $GCF$ in each group results to
\begin{array}{l}\require{cancel}
2y(y+4)-(y+4)
.\end{array}
Factoring the $GCF=
(y+4)
$ of the entire expression above results to
\begin{array}{l}\require{cancel}
(y+4)(2y-1)
.\end{array}