Answer
$\frac{5x}{7y^5}$
Work Step by Step
$\frac{25x^{-9}y^{-8} }{35 x^{-10} y^{-3}}$
$=\frac{ 25x^{10}y^3 }{35 x^9y^8}$
$=\frac{5\times5}{5\times7} \frac{x^{10} }{x^9} \frac{y^3}{y^8}$
$=\frac{5}{7} x^{10-9} y^{3-8}$
$=\frac{5}{7} x y^{-5}$
$=\frac{5x}{7y^5}$
