Respostas

  • Usuário do Brainly
2014-08-21T03:20:12-03:00
X² -2x -3=0

a=1
b=-2
c=-3

Δ=b²-4ac
Δ=2²-4.1.(-3)
Δ=4+12
Δ=16
√Δ=√16
√16= ± 4

x=(-b ± √Δ)/2a

x'= \frac{2+4}{2} = \frac{6}{2} =3

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

S={-1,3}