Question

ПОМОГИТЕ ДАЮ 20 БАЛЛОВ

$left { {{5m+2n=-2} atop {3m+2n=2}} right.$
$left { {{3x-3y=12} atop {3x+2y=17}} right.$
$left { {{8x-3y=41} atop {7x+5y=13}} right.$
$left { {{2x+4y=-1} atop {9x+7y=1}} right.$