Răspunsuri

2014-09-17T19:27:59+03:00
A -suma de bani pe care o are Ana
a+80-suma pe care o are Maria
(a+80)÷5 suma pe care o are Iulia
a+(a+80)+(a+80)÷5=272 ⇒ 2a+80+(a+80)/5=272 aducem la acelasi numitor(5) si scapam de numitor⇒  10a+400+a+80=1360 ⇒11a=1360-480 ⇒11a=880 ⇒a=80 lei
cum cu a am notat suma de bani a Anei ⇒ Ana are 80 lei
2014-09-17T19:29:45+03:00
Notam : a= ana,  m= maria,  i= iulia 

a+m+i= 272
m= a+80
i= a+80/5 

a+a+80+a+80/5= 272 (aducem la acelasi numitor) 
5a+5a+400+a+80= 1360
11a=1360-400-80
11a=88⇒a= 80lei (Alexandra) 

m= 80+80= 160lei (Maria)
i= 160:5= 32lei (Iulia)