Answer
$x^{19}y^{6}$
Work Step by Step
Based on the product rule for exponents, we know that $a^{m}\times a^{n}=a^{m+n}$ (where $m$ and $n$ are positive integers and $a$ is a real number).
Therefore, $(x^{9}y)\times(x^{10}y^{5})=x^{9+10}\times y^{1+5}=x^{19}\times y^{6}=x^{19}y^{6}$.