[tex]\frac{2}{\not5\,1}\cdot\not45\,9=\frac{2\cdot9}{1}=\boxed{18}\\\\1\frac{1}{5}\cdot85=\frac{6}{\not5\,1}\cdot\frac{\not85\,17}{1}=\frac{6\cdot17}{1}=\boxed{102}\\\\\frac{36}{4}=\boxed{9}\\\\\frac{1}{5}\cdot\frac{2}{\not3\,1}\cdot\not450\,150=\frac{1\cdot2\cdot150}{5\cdot1}=\frac{300}{5}=\boxed{60}[/tex]
