1. ( -1,2) is the same as (x=-1, y=2)
Substitute in your equation
y=3x-2
2=3•(-1)-2
2=-5 this is NOT true so (-1,2) is not a solution for the equation y=3x-2
2. (0,-2)
9x-6=3y
9(0)-6=3•(-2)
-6=-6 this is true so ( 0, -2) is a solution for the given equation