Question

resolva as equaçoes do 2 grau x2-x-20=0

Answer 1

x² - x - 20 = 0
a = 1
b = - 1
c = - 20

Δ = b² - 4ac
Δ = (-1)² - 4.1.(-20)
Δ = 1 + 80
Δ = 81

x = - b +/- √Δ
          2a
x = 1 + 9 = 10/2 = 5
        2

x = 1 - 9 = - 8/2 = - 4
       2

x = 5 e x = - 4