pls do #13 pls pls pls

y = 7
Simplifying numerators/ denominators
[tex]\frac{1+3}{-1+3}[/tex] = [tex]\frac{y-1}{2+1}[/tex]
[tex]\frac{4}{2}[/tex] = [tex]\frac{y-1}{3}[/tex]
2 = [tex]\frac{y-1}{3}[/tex] (cross- multiply )
y - 1 = 6 ( add 1 to both sides )
y = 7