Question

$left { {{x+xy+3y=3} atop {2x-xy-y=-2}} right.$

Answer 1

прибавим
3х+2у=1
у=0,5-1,5х
х+0.5х-1,5х²+1.5-4,5х-3=0
-1,5х²-3х-1,5=0
х²+2х+1=0
(х+1)²=0
х=-1
у=0,5+1,5=2
(-1;2)