2(3х+2у)+9=4х+21
2х+10=3-(6х+5у)
2(3х+2у)+9=4х+21
2х+10=3-6х-5у
8х=-5у-7
2(3х+2у)+9=4х+21
х=-0,625у-0,875
6х+4у+9=4х+21
х=-0,625у-0,875
2х + 4у=12
х=-0,625у-0,875
2(-0,625у-0,875) + 4у=12
х=-0,625у-0,875
-1,25у +4у =12+ 1,75
х=-0,625у-0,875
2,75у= 13,75
у= 5
х= -0,625*5-0,875
у=5
х=-4
ответ: (-4;5)
