Respostas

2014-08-07T08:20:41-03:00
{x+2y=6
{x2-y=2 (2)
-----------
{x+2y=6
{2 x2- 2y= 4
-----------
2 x2+x=10
2 x2+x-10=0
▲=b2 - 4ac
▲= 1 - 4×2(-10)
▲=1 - (-80)
▲=81
-----------------
x= -b +/- raiz de ▲/ 2a
-------------------
x= -(+1) +|- 9/2a
x= -1 +|- 9/4
x = -10/4 | 8/4
x = -5/2 e 2