Răspunsuri

2014-01-21T20:11:59+02:00
A+b=70
a/b=3/7
a=3b/7
3b/7+b=70
(3b+7b)/7=70
10b=490
b=49
a=3*49/7=3*7=21
2014-01-21T20:15:29+02:00
A+b=70=>a=70-b
a/b=3/7<=> (70-b)/b=3/7<=>3b=7(70-b)<=>3b=490-7b<=> 10b=490=>b=49
a=70-49=>a=21