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  • Usuário do Brainly
2014-05-23T01:57:37-03:00


a)   delta=b²-4ac      64-64=0

x=-b/2a    x-8/32= 1/4      s={ 1/4}  


b)   delta=49+120=169                                     S= {-2, 3/5}

x= 7+13/-10=20/-10=-2

x=7-13/10=-6/-10= 3/5


c)delta=16+8=24=2 √6  

x= -4 + ou -2√6/-2=-2(2+√6)/-2=2+√6            S={2+√6, 2-√6}

                               x=2-√6                                                       

1 5 1
2014-05-23T11:05:28-03:00
B)x=-b+-√b²-4ac/2a
x=7+-√(-7)²-4.(-5).6/2.(-5)
x=7+-√49+120/-10
x=7+-√169/-10
x=7+-13/-10
x'=20/-10⇒-2
x''=-6/-10⇒3/5
s⇒{-2,3/5}