Răspunsuri

2014-05-09T15:09:54+03:00
Carti=a
caiete=b
4a+18b=150
3b=a

4*3b+18b=150
12b+18b=150
30b=150
b=150:30
b=5 lei (un caiet=5 lei)

a=3*5
a=15 lei (carte=15 lei)