Respostas

2014-08-20T21:54:46-03:00
X²-6x+8=0
Δ= b²-4ac
Δ=36-4·1·(8)
Δ=36-36
Δ=0
-b₊₋√Δ
--------
2a

-(-6) +-0
--------------
2

6+0=6
6-0=6
6/2 =3


2014-08-20T21:55:53-03:00
Δ=(-6)∧2 - 4 × 1 × (+8)
Δ=36 - 32
Δ=4
x1= -(-6)+√4 / 2 × 1
x1= 6+2 / 2
x1=8 / 2
x1=4
x2= -(-6) -√4 /2  × 1
x2=6 - 2 / 2
x2=4 / 2
x2= 2
S={4;2}