Answer
$y^{11p}$
Work Step by Step
We are given the expression $y^{2p}\times y^{9p}$.
We can use the product rule to simplify, which holds that $a^{m}\times a^{n}=a^{m+n}$ (where a is a real number, and m and n are positive integers).
$y^{2p}\times y^{9p}=y^{2p+9p}=y^{11p}$