Answer
$x^{7a+5}$
Work Step by Step
We are given the expression $x^{5}\times x^{7a}$.
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).
$x^{5}\times x^{7a}=x^{5+7a}=x^{7a+5}$