Tìm x: a) (x - 2^2) - 4 = 0; b) (x^2 - 25)^2(x + 5)^2 = 0

Tìm x
a) (x - 2^2) - 4 = 0
b) (x^2 - 25)^2(x + 5)^2 = 0