Respostas

2013-07-18T09:59:51-03:00
Delta =(b)^2 -4ac
D= 9-4.1(-4)
D= 25 

x=(-b- ou+ raiz de D)/2a
x1=3 +5/2
x1= 4
x2=3-5/2
x2=-1    

1 4 1
2013-07-18T22:38:59-03:00

x=b-4xaxc
x=(-3)²-4x1x(-4)
x=9-(-16)
x=25

x'=-(-3)+5/2=8/2=4

x"=-(-3)-5=/2=-2/2=-1

 Então x=(4,-1)