Respostas

2014-06-03T22:37:18-03:00
2x²-x-3=0
a) 2 b) -1 c) -3 
delta = (-1)² (-4 .2 . -3)
        = 1 + 24
        = 25
x= -(-1) +/- raiz de 25/ 2*2
x= 1 +/- 5/4
x'= 1+5/4
x'= 6/4
x'=3/2

x''= 1-5/4
x''= -4/4
x''= -1