#### Answer

$\dfrac{9x^{2}}{y}\cdot\dfrac{4y}{3x^{3}}=\dfrac{12}{x}$

#### Work Step by Step

$\dfrac{9x^{2}}{y}\cdot\dfrac{4y}{3x^{3}}$
Multiply both rational expression and simplify by removing repeated factors in the numerator and the denominator:
$\dfrac{9x^{2}}{y}\cdot\dfrac{4y}{3x^{3}}=\dfrac{(9x^{2})(4y)}{(y)(3x^{3})}=\dfrac{36x^{2}y}{3x^{3}y}=\dfrac{12}{x}$