Answer
$(y^2+1)(x^3-3)$
Work Step by Step
$\bf{\text{Solution Outline:}}$
Group the terms of the given expression, $
x^3y^2-3-3y^2+x^3
,$ such that the factored form of the groupings will result to a factor common to the entire expression. Then, factor the $GCF$ in each group. Finally, factor the $GCF$ of the entire expression.
$\bf{\text{Solution Details:}}$
Grouping the first and fourth terms and the second and third terms, the given expression is equivalent to
\begin{array}{l}\require{cancel}
(x^3y^2+x^3)+(-3-3y^2)
.\end{array}
Factoring the $GCF$ in each group results to
\begin{array}{l}\require{cancel}
x^3(y^2+1)-3(1+y^2)
\\\\=
x^3(y^2+1)-3(y^2+1)
.\end{array}
Factoring the $GCF=
(y^2+1)
$ of the entire expression above results to
\begin{array}{l}\require{cancel}
(y^2+1)(x^3-3)
.\end{array}