Question

2х -у =-6
х+2у=7
решить систему уравнений

Answer 1

x+2y=7 x=7-2y
2x-y=-6 2 (7-2y)-y=-6
14-4y-y=-6
-5y=-20
y=4
y=4
x=-1

Answer 2

$left { {{2x-y=-6} /*2atop {x+2y=7}} right. \ left { {{4x-2y=-12} atop {x+2y=7}} right. \ 5x=-5 \ x=-5/5\x=-1 \ \ -1+2y=7 \ 2y=7+1 \ 2y=8\y=8/2\y=4 \ \ left { {{y=4} atop {x=-1}} right.$