Respostas

2013-09-08T15:11:46-03:00
 x^{2} -3x-4=0
 -3^{2}{2} -4.1.(-4)=0 9+16=25 o delta é 25 -(-3)+-[tex] \sqrt{25} /2=
x ' 3+5/2=8/2=4
x'' 3-5/2=-2/2=-1