Question

2x +y=1 3x-5y=21 система​

Answer 1

Ответ: x=2, y= -3

Объяснение:

$\left \{ {{2x +y=1 } \atop {3x-5y=21}} \right. \\\\ \left \{ {{y=1-2x } \atop {3x-5(1-2x)=21}} \right. \\\\ \left \{ {{y=1-2x } \atop {3x-5+10x=21}} \right. \\\\ \left \{ {{y=1-2x } \atop {13x=26}} \right. \\\\ \left \{ {{y=1-2*2 } \atop {x=2}} \right. \\\\ \left \{ {{y=-3 } \atop {x=2}} \right.$