Question

intr-o florarie sunt 492 de trandafiri albi si rosii. fiecarui trandafir alb ii corespund 3 trandafiri rosii. cati trandafiri sunt din fiecare fel?

Answer 1

a+r=492
a=3r
3r+r=492
4r=492
r=492:4
r=123
a+r=492
a+123=492
a=492-123
a=369
369+123=492

sau 
a=3r
a=3*123
a=369
succes!

Answer 2

noyam prin x , y trandafiri
x+y= 492
x=3y
3y+y=492
4y=492
y=492 impartit la 3 
y=123
x+y=392
x+123=492
x=492-123
x=369
Verificare  369+123=492