Respostas

2014-03-15T18:29:50-03:00
-x2+6x-9=0 

4x=0+9
4x=9
9/4
2.25
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o valor de X= 2.25
-x2 = 2.25x2
6x= 2.25x6
2014-03-15T18:30:09-03:00
Por baskara
delta = b2 - 4ac
a = -1
B = 6
C = -9
Delta = 6'2 - 4.-1.9
Delta = 36 + 36
Delta = 72
X = -b+ou- raiz de delta / 2.a
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