Answer
$5^{10}$
Work Step by Step
We are given the numbers $5^{10}$ and $5^{9}$. Without calculating, we know that $5^{10}$ will be bigger. Since both numbers have the same base (and the base is positive), we know that the number with the larger exponent will be larger.
Without calculating, we know that $5^{10}$ will be $5^{10-9}=5^{1}=5$ times larger than $5^{9}$.