Answer
$= \frac{4x}{9}$
Work Step by Step
In order to solve, first multiply the fractions together. Then, cancel out common factors in the numerator and the denominator of the fraction to obtain:
$= (\frac{7x^{2}}{9y})(\frac{12y}{21x})$
$= \frac{84x^{2}y}{189xy}$
$= \frac{4x}{9}$
