Question

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

Answer 1

Olá, Nandinhagomes20!

x² - x - 20 = 0

a = 1
b = -1
c = -20

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

x = -b +- √Δ / 2.a
x = -(-1) +- √81 / 2.1
x = 1 +- 9 / 2

x' = 1+9/2 = 10/2 = 5
x'' = 1-9/2 = -8/2 = -4

S = {5, -4}

Answer 2

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