Answer
$$a^3bxy^2$$
Work Step by Step
Simplifying the expression using the rules of radicals, we find:
$$ \frac{7\sqrt{a^2b}\sqrt{25xy}}{5\sqrt{a^{-4}b^{-1}}\sqrt{49x^{-1}y^{-3}}}\\ \frac{5a\sqrt{b}\sqrt{xy}}{\frac{5}{a^2\sqrt{b}\sqrt{x}y^{\frac{3}{2}}}}\\ a^3bxy^{\frac{3}{2}+\frac{1}{2}}\\ a^3bxy^2$$
