the conjugate of a binomial is simply the same binomial with a different sign in the middle, so the conjugate of x + y, is just x - y, and the conjugate of w - z is just w + z and so on.
now, complex roots never come all by their lonesome, her sister, the conjugate, is always along with her, so if the root a + bi is there, then her sister a - bi is also there too.
