Answer
1
Work Step by Step
$\displaystyle \frac{3^{-5/2}\cdot 3^{3/2}}{3^{7/2}\cdot 3^{-9/2}}$=...use: $a^{m}\cdot a^{n}=a^{m+n}$
= $\displaystyle \frac{3^{-5/2+3/2}}{3^{7/2-9/2}}$
=$\displaystyle \frac{3^{-2/2}}{3^{-2/2}}$
=$\displaystyle \frac{3^{-1}}{3^{-1}}$ = 1