Answer
$\frac{5\sqrt {14xy}}{21y}$
Work Step by Step
We don't want to leave radicals in the denominator, so to get rid of radicals in the denominator, we multiply both the numerator and denominator by the denominator:
$\frac{5\sqrt {2x}}{3\sqrt {7y}} • \frac{3\sqrt {7y}}{3\sqrt {7y}}$
Multiply to simplify:
$\frac{15\sqrt {14xy}}{9\sqrt {49y^2}}$
Take the square root of any perfect squares:
$\frac{15\sqrt {14xy}}{9 • 7 • y\sqrt {49y^2}}$
Multiply coefficients:
$\frac{15\sqrt {14xy}}{63y}$
Divide numerator and denominator by any factors common to both:
$\frac{5\sqrt {14xy}}{21y}$
