Respostas

  • Usuário do Brainly
2014-05-20T17:23:05-03:00
x² - 7x - 2c = 0
(- 3)² - 7 . (- 3) - 2c = 0
9 + 21 - 2c = 0
30 - 2c = 0
- 2c = - 30 . (- 1)
2c = 30
c = 30/2
c = 15