Answer
$=\frac{y^{2}}{25x^{6}}$
Work Step by Step
$$(\frac{5x^{3}}{y})^{-2}$$
When raising a quotient to a power, raise both the numerator and denominator to the power:
$$=\frac{(5x^{3})^{-2}}{y^{-2}}$$
When raising a product to a power, raise each factor to that power:
$$=\frac{5^{-2}x^{(3\times(-2)}}{y^{-2}}$$
$$=\frac{5^{-2}x^{-6}}{y^{-2}}$$
Move the base with the negative exponent to the other side of the fraction, and make the exponent positive:
$$=\frac{y^{2}}{5^{2}x^{6}}$$
$$=\frac{y^{2}}{25x^{6}}$$
