Question

Решите систему уравнений
{5х+у=30
{3х-4у=41

Answer 1

$\left \{ {{5x+y=30}|*4 \atop {3x-4y=41}} \right.\\\\+\left \{ {{20x+4y=120} \atop {3x-4y=41}} \right.\\-------\\23x=161\\\\x=7\\\\y=30-5x=30-5*7=30-35=-5\\\\y=-5$

Ответ : (7 ; - 5)