Answer
a) $\frac{1}{yz^{3}}$
b) $\frac{y^8}{x^{12}}$
Work Step by Step
a) $\frac{y^{-2}z^{-3}}{y^{-1}}$ = $y^{-1}$$z^{-3}$= $\frac{1}{yz^{3}}$
b) ($\frac{x^3y^{-2}}{x^{-3}y^{2}}$)$^{-2}$ = (${x^{3+3}y^{-2-2}}$)$^{-2}$ = $x^{(6)(-2)}$$y^{(-4)(-2)}$ = $x^{-12}$$y^{8}$ = $\frac{y^8}{x^{12}}$