Question

resilva a equaçao do 2grau: X² -2X -8=0

Answer 1

x² - 2x - 8 = 0
a = 1; b = - 2; c = - 8

Δ = b² - 4ac
Δ = (-2)² - 4.1.(-8)
Δ = 4 + 32
Δ = 36

x = - b +/- √Δ
           2a

x = - ( - 2) +/- √36
            2.1

x' = 2 + 6 = 8/2 = 4
         2

x" = 2 - 6 = - 4/2 = - 2
         2

R.: x = 4 e x = - 2