En un cajón hay 720 bolas entre rojas, verdes y azules?

Solución :

De los datos :

rojas = a

verdes = b

azules = c

a = 2(b + c)

b = c²

a + b + c = 720

a = 2(c² + c)

2(c² + c) + c² + c = 720

2c² + 2c + c² + c = 720

3c² + 3c = 720

3(c² + c) = 240× 3

(c² + c) = 240

c(c + 1) = 24 × 10

c(c + 1) = 2× 12 ×10

c(c + 1) = 2× 12× 5× 2

c(c + 1) = 2× 6× 2× 5× 2

c(c + 1) = 2× 3× 2× 2× 5× 2

c(c + 1) = 15× 16

c = 15

a = 2(c² + c)

a = 2(15² + 15)

a = 2(15² + 15)

a = 2(225 + 15)

a = 2(240)

a = 480

b = c²

b = 15²

b = 225

a = 480

b = 225

c = 15.