we must take the ratio and simplify
[tex]\frac{21}{28}\longrightarrow\frac{3}{4}[/tex][tex]\frac{96}{32}\longrightarrow\frac{3}{1}[/tex][tex]\frac{22}{33}\longrightarrow\frac{2}{3}[/tex][tex]\frac{12}{36}\longrightarrow\frac{1}{3}[/tex][tex]\frac{72}{56}\longrightarrow\frac{9}{7}[/tex][tex]\frac{54}{63}\longrightarrow\frac{6}{7}[/tex]