So for this question (for finding x and y) you will want to use elimination. To do this you will need to bring the x and y to the same side (I put them on the left):
-3/2x+y=6
x+y=0
Now subtract the y on the bottom from the top to isolate x:
3/2x=6
Now the easiest way to bring over the 3/2 to isolate the x fully is to convert it to decimal (1.5) and divide it by 6 (because when multiplication on one side of problem the only way to bring it over is to divide):
x=6/1.5
which simplifies to:
x=4
Hope this helps!
