Question

1. Encontre as raízes das equações:
a) x² - 5x + 6 = 0
b) x² + 2x - 3 = 0
c) x² - 4x + 3 = 0
d) x² - 11x + 28 = 0
e) x² - 3x - 10 = 0

Answer 1

a) Δ = 25 - 4 . 1 . 6 = 25 - 24 = 1
√Δ = 1
x' = (5 + 1) / 2 = 6/2 = 3
x" = (5 - 1) / 2 = 4/2 = 2

b) Δ = 4 - 4 . 1 . (-3) = 4 + 12 = 16
√Δ = 4
x' = (-2 + 4) / 2 = 2/2 = 1
x" = (-2 - 4) / 2 = -6/2 = -3

c) Δ = 16 - 4 . 1 . 3 = 16 - 12 = 4
√Δ = 2
x' = (4 + 2) / 2 = 6/2 = 3
x" = (4 - 2) / 2 = 2/2 = 1

d) Δ = 121 - 4 . 1 . 28 = 121 - 112 = 9
√Δ = 3
x' = (11 + 3) / 2 = 14/2 = 7
x" = (11 - 3) / 2 = 8/2 = 4

e) Δ = 9 - 4 . 1 . (-10) = 9 + 40 = 49
√Δ = 7
x' = (3 + 7) / 2 = 10/2 = 5
x" = (3 - 7) / 2 = -4/2 = -2