Tìm x: 5x ( x - 3)^2 - 5(x - 1)^3 + 15 (x + 2)(x - 2) = 5; x^2(x^2 + 1) - x^2 - 1

Tìm x:
a. 5x ( x - 3)^2 - 5(x - 1)^3 + 15 (x + 2)(x - 2) = 5
b. x^2(x^2 + 1) - x^2 - 1
CÁM ƠN TRC