i assume you are asking when they are equal. to make them equal we can add the equations together easily since we have x in one and - x in the other.
to add equations you have to add one side of the equal sign to one side of the other equations equal sign. then you must do the same with the sides of the equal signs you did not already use. you must do both sides or it will not work.
so i will add both left sides together and right sides.
x + 2y + (3y - x) = 3 + 2
5y = 5
y = 1
plug y into one equation.
x + 2 (1) = 3
x = 1
so we get (1,1)
plug into other equation to check answer
3 (1) - (1) = 2
2 = 2
since this is true the answer is correct