Respostas

2013-11-13T07:43:30-02:00
A) 
a = -1
b = -9
delta = b²-4ac
delta = (-9)² - 4.(-1).0
delta = 81 --> delta > 0 --> dois zeros diferentes

b)
(x²/4)+2x = 0
a = 1/4
b = 2
delta = b²-4ac
delta = 2² - 4.1/4.0
delta = 4
delta > 0 --> dois zeros reais