Let:
[tex]k\cdot RT=TU[/tex]
Where:
k = Constant of proportionality
[tex]\begin{gathered} k\cdot4=6 \\ solve_{\text{ }}for_{\text{ }}k \\ k=\frac{6}{4} \\ k=\frac{3}{2} \end{gathered}[/tex]
So:
[tex]\begin{gathered} k\cdot RS=UV \\ \frac{3}{2}(6)=UV \\ \frac{18}{2}=UV \\ UV=9 \end{gathered}[/tex]
