Question

Intr-o gradina cresc de 3 ori mai multi trandafiri rosii decat galbeni. Daca s-ar mai planta 40 de trandafiri galbeni, atunci ar fi tot atate cat rosii.
Cati trandafiri cresc in total in gradina?

Answer 1

Fie r - nr. trandafiri rosii, g - nr trandafiri galbeni.

r=3g
g+40=r

Deci, g+40=3g \ -g (Scadem "g")
40=2g
g=20

r=3*20
r=60

Total : r+g=60+20=80 trandafiri 

Answer 2

r = 3g
r = g + 40
3g = g + 40
2g = 40
g = 40 : 2
g = 20 trandafiri galbeni
r = 3 * 20
r = 60 trandafiri rosii
20 + 60 = 80 trandafiri in total
20 + 40 = 60 trandafiri galbeni