Answer
$\frac{5q}{t}$
Work Step by Step
$\frac{45pqrs}{9prst}\longrightarrow$ Use prime factorization.
$\frac{(3\times3\times5)pqrs}{(3\times3)prst}\longrightarrow$ Identify factors that can cancel (identified with a line over).
$\frac{(\overline{3\times3}\times5)\overline{p}\ q\ \overline{rs}}{(\overline{3\times3})\overline{prs}\ t}\longrightarrow$ Eliminate canceled factors.
$\frac{5q}{t}$
