Question

Решить систему уравнения:

(2x+3y=3;

(x-2y=5;

Answer 1

$left { {{2x+3y=3;} atop {x-2y=5;}} right.\ left { {{2x+3y=3;} atop {x=2y+5;}} right.\ left { {{2(2y+5)+3y=3;} atop {x=2y+5;}} right.\ left { {{4y+10+3y=3;} atop {x=2y+5;}} right.\ left { {{7y+10=3;} atop {x=2y+5;}} right.\ left { {{7y=3-10;} atop {x=2y+5;}} right.\ left { {{7y=-7;} atop {x=2y+5;}} right.\ left { {{y=-1;} atop {x=2y+5;}} right.\ left { {{y=-1;} atop {x=2*(-1)+5;}} right.\ left { {{y=-1;} atop {x=3}} right.$

ответ: (3;-1)

Answer 2

выражаем х через у,х=5+2у

2(5+2у)+3у=3

7у=3-10

у=-1

х=5+2(-1)=3

ответ:(3;-1)