x-2y=5
3x-y=0 /*(-2)
x-2y=5
-6x+2y=0
------------- +
-5x=5/:(-5)
x=-1
-1-2y=5
-2y=5+1/:(-2)
y=-3
x=-1
y=-3
x - 2y = 5 / *(-1)
3x - y = 0 / *2
-x + 2y = -5
6x - 2y = 0
----------------
5x = -5
x = -1
x - 2y = 5
-1 - 2y = 5
-2y = 5 + 1
-2y = 6
y = -3
x = -1
y = -3
