Answer
$(-5)^{13}$
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, $(-5)^{7}\times(-5)^{6}=(-5)^{7+6}=(-5)^{13}$.