Answer
$y^3+6y^2+12y+8$
Work Step by Step
Using $(a\pm b)^3=a^3\pm3a^2b+3ab^2\pm b^3$ or the cube of a binomial, the expression, $
(y+2)^3
,$ is equivalent to
\begin{array}{l}\require{cancel}
(y)^3+3(y)^2(2)+3(y)(2)^2+(2)^3
\\\\=
y^3+3(y^2)(2)+3(y)(4)+8
\\\\=
y^3+6y^2+12y+8
.\end{array}
