Răspunsuri

2014-05-06T22:11:07+03:00
A/b=3/7   ⇒ 7a=3b⇒    a=3b/7
2a+3b=2700  inlocuim
2·3b/7+3b=2700
6b/7+3b=2700  aducem la acelasi numitor
(6b+21b)/7=2700
27b/7=2700
b=2700·7/27
b=700
a=3b/7=3·700/7
a=300
verificare
2·300+3·700=2700
600+2100=2700