## Elementary Algebra

$81a^{2}b^{6}$
We simplify this equation by raising each term in the expression to the power of $2$: $(9ab^{3})^{2}$ =$9^{2}\times a^{2}\times (b^{3})^{2}$ =$81\times a^{2}\times (b^{3\times2})$ =$81\times a^{2}\times (b^{6})$ =$81a^{2}b^{6}$