Respostas

  • Usuário do Brainly
2014-07-10T17:34:09-03:00
A)
x²-8x-9=0

Δ=b²-4ac
Δ=64+36
Δ=100
√Δ=10
x'= \frac{8+10}{2} = \frac{18}{2} =9

x"= \frac{8-10}{2} = \frac{-2}{2} =-1

S={-1,9}


x²-6x+5=0
Δ=b²-4ac
Δ=36-20
Δ=16
√Δ=4

x'= \frac{6+4}{2} = \frac{10}{2} =5

x"= \frac{6-4}{2} = \frac{2}{2} =1

S={1,5}