Answer
See below.
Work Step by Step
$\frac{g(x)}{f(x)}=\frac{5x^{1/2}}{4x^{2/3}}=\frac{5}{4}\frac{x^{1/2}}{x^{2/3}}=0.8x^{1/2-2/3}=1.25x^{-1/6}$
The function is undefined for negative numbers, so the domain is the non-negative real numbers. However, 0 also cannot be a solution since it would make the denominator 0.
