Question

Ре­ши­те си­сте­му урав­не­ний

Answer 1

$left { {{5x-y=7} atop {3x+2y=-1}} right.$ |*2

$left { {{10x-2y=14} atop {3x+2y=-1}} right.$
$13x=13$

$left { {{x=13:13} atop {5x-y=7}} right.$

$left { {{x=1} atop {5*1-y=7}} right.$

$left { {{x=1} atop {y=7-5}} right.$

$left { {{x=1} atop {y=2}} right.$

Ответ: х=1, у=2