Question

Resolva a equação do 2• grau: x2-x-20=0

Answer 1

x² - x - 20 = 0

Delta = b² - 4ac
Delta = 1 - 4(1)(-20)
Delta = 1 + 80
Delta = 81

X = (-b +- raiz delta) / 2a
X = (1 +- 9) / 2
x' = 10/2 = 5
x" = -8/2 = -4