4 = 0; c) x^2 - 2x√5 + 5 = 0; d) (x - 1)^2 = (2x - 1)^2

Tìm x:
a) 8x^3 + 36x^2 + 54x + 27 > 0
b) 4x^2 - 2x + 1/4 = 0
c) x^2 - 2x√5 + 5 = 0
d) (x - 1)^2 = (2x - 1)^2