Question

решите систему уравнений х/3 у/4 и х+у 5

Answer 1

x/3=-y/4
x+y=5

x=5-y

(5-y)/3=-(y/4)
(5-y)/3+y/4=0
4(5-y)/12+3y/12=0
(20-4y+3y)/12=0
(20-y)/12=0
y=20

x+20=5
x=5-20=-15

Ответ: x=-15  y=20