Tìm x: a) x(x + 2) = 0. b) (x - 3)(x - 5) = 0. c) (x - 2)(x^2 - 1) = 0. d) (x - 1)(x^2 + 1) = 0

a) x(x + 2) = 0
b) (x - 3)(x - 5) = 0
c) (x - 2)(x^2 - 1) = 0
d) (x - 1)(x^2 + 1) = 0