if you multiply equation 2 by 3 , you get -6x+3y=24
if we subtract -6x+3y=24 from 2x -3y =12,
we get
2x-3y-(-6x+3y)=12-24
2x-3y+6x-3y=-12
8x-6y=-12,
After this actions we did not remove any variable, but with the elimination method we had to remove one variable, to get equation with another one variable. So 3 is incorrect