The given expression :
5/ y-7 = 3/ y-5
[tex]\begin{gathered} \frac{5}{y-7}=\frac{3}{y-5} \\ Apply\text{ Cross multiplication} \\ 5(y-5)=3(y-7) \\ 5y-25=3y-21 \\ \text{Seperate variable and constant term} \\ 5y-3y=25-21 \\ 2y=4 \\ y=\frac{4}{2} \\ y=2 \end{gathered}[/tex]Answer : y = 1