[tex] \frac{x}{7} = \frac{y}{5} \ \textless \ =\ \textgreater \ 5x=7y \ \textless \ =\ \textgreater \ x= \frac{7y}{5} [/tex]
[tex] \frac{7y}{5} +y=12 [/tex]
Aducem la numitor comun, 5
[tex] \frac{7y}{5} + \frac{5y}{5} = \frac{60}{5} \ \textless \ =\ \textgreater \ 12y=60 =\ \textgreater \ y=5 si x=7[/tex]
