Question

1. simplify $a^{4}a^{5}$. $2a^{9}$ $a^{20}$ $2a^{20}$ $a^{9}$

Explanation:

Step1: Apply exponent product rule

When multiplying like bases, add exponents: $a^m \cdot a^n = a^{m+n}$

Step2: Substitute values and calculate

$a^{4+5} = a^9$

Answer:

$a^9$ (the last option)