Question

x dois menos x igual a zero

Answer 1

x² - x = 0
Δ = 1 - 0
Δ = 1
x = 1 +-√1/2
x = 1 +-1/2
x' = 1+1/2
x' = 2/2 = 1
x'' = 1-1/2
x'' = 0/2 = 0        ok