Answer :
[tex] \left \{ {{-2+6y=18} \atop {3y=15}} \right. \\ +2+2 \left \{ {{6y=20} \atop {3y=15}} \right. \\ /3/3 \left \{ {{6y=20} \atop {y=5}} \right.\\ /6/6 \left \{ {{y=3 \frac{1}{3} } \atop {y=5}} \right. [/tex]
[tex]-2+6y=18\ \ \ |add\ 2\ to\ both\ sides\\6y=20\ \ \ \ \ |divide\ both\ sides\ by\ 6\\y=\frac{20}{6}\\\\\boxed{y=\frac{10}{3}}\\---------------------\\\\3y=15\ \ \ \ \ |divide\ both\ sides\ by\ 3\\\\\boxed{y=5}[/tex]
