Respostas

2013-05-20T19:22:50-03:00

a) \Delta = 6² - 4 . 9 . 0

   ''   = 36

 x1 = -6 - 6 / 2.9

x1 = -12 / 18

x1 = - 2 / 3

 

x2 = -6 + 6 / 2.9

x2 =  0 / 18

x2 = 0

 

b) x²-25 = 0    -----> x² = 25 -------> x = \sqrt {25} -------> x = +- 5