{(15x-3y)/4 + (3x+2y)/6=3 /*12⇒45x-9y+6x+4y=36⇒51x-5y=36/*7
{(3x+y/)3 + (x-3y)/2=6 /*6⇒6x+2y+3x-9y=36⇒9x-7y=36/*(-5)
{357x-35y=252
{-45x+35y=-180
прибавим
312x=72
x=72/312
x=3/13
9*3/13-7y=36
7y=27/13-36
7y=-33 12/13
y=-33 12/13:7
y=-441/91
y=-4 77/91
y=-4 11/13