Answer
$81x^{11}$
Work Step by Step
When a power is raised to a power, we multiply the two powers, so we multiply 2 and 1/2 for the first set of parenthesis and multiply 5 and 2 for the second set of parenthesis. Also, because we raise everything in the first parenthesis to the 2nd power, we also raise 9 to the 2nd power. Thus we obtain:
$81x \times x^{10}=81x^{11}$
