3.
[tex]y + 3x = - 2 \\ 2y - 3x = 14[/tex]
To find y, it's easiest to use the elimination method since 3x can already be canceled by adding.
[tex]3y =12[/tex]
Divide by 3
[tex]y = 4[/tex]
4.
[tex] - 3x + 5y = 10 \\ 3x + 7y = 14[/tex]
Elimination is easiest to find y, the x is canceled out by adding every number.
[tex]12y = 24[/tex]
Divide by 12
[tex]y = 2[/tex]