Question

Найти х и у из системы:
4х+7у+13=0
7х-4у+108=0

Answer 1

$\left \{ {{4x+7y+13=0} \atop {7x-4y+108=0}} \right. <=>\left \{ {{16x+28y=-52} \atop {49x-28y=-756}} \right. =>65x=-808=>x=-\frac{808}{65}=>\\=>y=\frac{341}{65}$