m(x) = x² - 4x + 3
m(x) = x² - x - 3x + 3
m(x) = x(x - 1) - 3(x - 1)
m(x) = (x - 3)(x - 1)
(x - 3)(x - 1) = 0
x - 3 = 0 ∧ x - 1 = 0
x = 3 ∧ x = 1
or
m(x) = x² - 4x + 3
Δ = (-4)² - 4 · 1 · 3
Δ = 16 - 12 = 4
√Δ = √4
√Δ = 2
x = (4 - 2)/2 ∧ x = (4 + 2)/2
x = 2/2 ∧ x = 6/2
x = 1 ∧ x = 3
