Respostas

2014-04-02T16:37:10-03:00
X (2x + 1) /3 = 5

2x² + x/3 = 5
2x² + x = 3.5
2x² + x - 15 = 0

Agora faz por Bháskara

a = 2  b= 1  c= -15

Δ= b² -4ac
Δ = 1 - 4.2.(-15)
Δ = 1 + 120
Δ = 121

x = -b +/- √Δ
         2a

x = -1 +/- 11
         4

x' = -1 + 11/4
10/4 = 5/2

x" = -1 -11/4
-12/4 = -3

Espero ter ajudado (: