Answer
$y^2-y-6$
Work Step by Step
Using $(a+b)(c+d)=ac+ad+bc+bd$ or the product of $2$ binomials, the given expression, $
(y+2)(y-3)
$, is equivalent to
\begin{array}{l}\require{cancel}
y(y)+y(-3)+2(y)+2(-3)
\\\\=
y^2-3y+2y-6
\\\\=
y^2-y-6
.\end{array}