Respostas

2014-08-10T15:59:44-03:00
Olá, Pablopere2008!

x² - 7x - 2c = 0
(-3)² - 7.(-3) - 2c = 0
9 + 21 - 2c
30 - 2c = 0
30 = 2c
2c = 30
c = 30 / 2
c = 15
2014-08-10T16:00:26-03:00
X² - 7x - 2c = 0
(-3)² - 7*(-3) - 2c = 0
9 + 21 - 2c = 0
- 2c = - 30
c = - 30 ÷ (-2)
c = 15