Tìm x

Tìm x :
a) 50x^2 - 25x = 0
b) 3x^3 (2x - 1) = 0
c) x^2 + 4x^2 +4x = 0 
d) 8x^3 - 32x = 0 
e) x^2 (x + 3) + 4x + 12 = 0