Respostas

2014-02-16T20:02:39-03:00
X²-8x+7=0

a= 1
b = -8
c = 7

Delta = b²-4.a.c
Delta = (-8)²-4.1.7
Delta = 64-28
Delta = 36

-b+/- Vdelta / 2.a
-(-8) + 6 /2.1
14 / 2 =
7

-(-8) - 6 /2
2/2 =
1

8 4 8
2014-02-16T20:03:45-03:00
Com delta e baskhara 
a)1 b)8 c)7
Δ=b² -4.a.c
Δ=8² -4.1.7
Δ=64 - 28
Δ= 36

x=-b +/- √Δ
     2.a
x= -8 +/- 6
        2
x1= 7
x2=-1
10 4 10