Question

In 15 vase cu capacitatea de 2litri respectiv 5 litri avem 60 de litri de apa.cate vase de fiecare fel avem

Answer 1

2x+5y=60
x+y=15, deci x=15-y, inlocuiesc in prima
30-2y+5y=60, 3y=30, y=10, deci 10 vase de 5 l,
x=15-10=5(vase de 2 l)

Answer 2

Fie a=vas 2l si b=vas 5l
a+b=15=>a=15-b
2a+5b=60
2(15-b)+5b=60
30-2b+5b=60
3b=30
b=10 vase de 5l
a=  5 vase de 2l