[tex]\displaystyle a). \frac{x}{3} = \frac{16}{9} \Rightarrow 9x=3 \cdot 16 \Rightarrow 9x=48 \Rightarrow x= \frac{48}{9} ^{(3} \Rightarrow \boxed{x= \frac{16}{3} } \\ b). \frac{15}{y} = \frac{5}{8} \Rightarrow 15 \cdot 8=5y \Rightarrow 120=5y \Rightarrow y= \frac{120}{5} \Rightarrow \boxed{y=24} \\ c). \frac{18}{7} = \frac{z}{9} \Rightarrow 18 \cdot 9=7z \Rightarrow 162=7z \Rightarrow \boxed{z= \frac{162}{7} } [/tex]
[tex]\displaystyle d). \frac{4}{13} = \frac{3}{t} \Rightarrow 4t=13 \cdot 3 \Rightarrow 4t=39 \Rightarrow \boxed{t= \frac{39}{4} } \\ e). \frac{u}{20} = \frac{7}{9} \Rightarrow 9u=20 \cdot 7 \Rightarrow 9u=140 \Rightarrow \boxed{u= \frac{140}{9} }[/tex]
