Question

Найдите сумму решений системы уравнений
5х-3у=4
х+3у=8

Answer 1

$left { {{5x-3y=4} atop {x+3y=8}} right. left { {{x=8-3y} atop {5*(8-3y)-3y=4}} right. 40-15y-3y-4=0 36-18y=0 -18y=-36 y=2 x=8-3*2=2$