Answer
$27y^{5}+24y^{4}-20y^{3}+25y^{2}$
Work Step by Step
$ \begin{array}{lllllll}
& & & & 9y^{3} & -7y^{2} & +5y\\
& & & & & 3y^{2} & +5y\\
& & & & -- & -- & --\\
& & & & 45y^{4} & -35y^{3} & +25y^{2}\\
& & & 27y^{5} & -21y^{4} & +15y^{3} & \\
\hline & & & & & & \\
& & & 27y^{5} & +24y^{4} & -20y^{3} & +25y^{2}
\end{array} \qquad \begin{array}{l}
.\\
.\\
.\\
\leftarrow 5y(9y^{3}-7y^{2}+5y)\\
\leftarrow 3y^{2}(9y^{3}-7y^{2}+5y)\\
\\
\leftarrow\text{combine }
\end{array}$