Respostas

2013-11-28T16:33:09-02:00
Δ = (5²) - 4 . 2 . (- 7) 
Δ = 25 + 56
Δ = 81
-----
x' = - 5 + 9 / 4 
4 / 4 =
x' = 1
-----
x'' = - 5 - 9 / 4 
- 14 / 4 =
x'' = - 7 / 2

S = (1, -7/2)