Question

Помогите срочно...................................

Answer 1

$left { {{2x+3y=-11} atop {2x-3y=7}} right. |+ left { {{4x=-4} atop {2x-3y=7}} right. left { {{x=-1} atop {-3y=9}} right. left { {{x=-1} atop {y=-3}} right.$

$left { {{4x-y=27} atop {4x+y=29}} right. |+ left { {{4x-y=27} atop {8x=56}} right. left { {{-y=-1} atop {x=7}} right. left { {{y=1} atop {x=7}} right.$

$left { {{-x-9y=33} atop {9y-x=-21}} right. |+ left { {{x+9y=-33} atop {-2x=12}} right. = left { {{9y=-27} atop {x=-6}} right. left { {{y=-3} atop {x=-6}} right.$

$left { {{9y-8x=89} atop {-9y-8x=-73}} right.|+ left { {{-16x=16} atop {9y+8x=73}} right. left { {{x=-1} atop {9y=81}} right. left { {{x=-1} atop {y=9}} right.$

Answer 2

а почему в послднем 1 и 9

Answer 3

-1