Answer
$a^{2/3}b^{2}$
Work Step by Step
$\displaystyle \frac{a^{4/3}}{a^{2/3}} \cdot \displaystyle \frac{b^{1/2}}{b^{-3/2}}\qquad$ ....... use $\displaystyle \frac{a^{m}}{a^{n}}=a^{m-n}$
$=a^{4/3-2/3}\cdot b^{1/2-(-3/2)}\qquad$ .......simplify exponents
$=a^{2/3}b^{4/2}$
$=a^{2/3}b^{2}$
