## Algebra: A Combined Approach (4th Edition)

$a^{9}$
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, $a^{2}a^{3}a^{4}=a^{2+3+4}=a^{9}$.