Respostas

2013-08-09T09:34:36-03:00
∆= b2- 4.a.c                                           
 ∆= 02- 4.2.(-98)                               
  
 ∆=√ 784

∆=28
x’= 0+28/2.2= 28/4= 7     
  x”=0-28/4= -7     S={7,-7}