Answer
$16y^2+42y-49$
Work Step by Step
Using the $(a+b)(c+d)=ac+ad+bc+bd$ or the FOIL Method and the laws of exponents, the given expression, $
(8y-7)(2y+7)
,$ simplifies to
\begin{array}{l}\require{cancel}
8y(2y)+8y(7)-7(2y)-7(7)
\\\\=
16y^2+56y-14y-49
\\\\=
16y^2+42y-49
.\end{array}
