Problema 10 dau coroana, metoda grafica

Răspuns:
a+b+c=643 lei
a |___|
b |___|___|
c |___|___|+18 }643
5p+18=643
5p=643-18
5p=625
p=625÷5
p=125 (lei in prima luna)
125×2=250 (lei a doua luna)
(125×2)+18=268( lei a treia luna)
verificare
125+250+268=643 lei
Succes!