Thu gọn: a) (1 + 2x) + 2(1 + 2x)(x - 1) + (x - 1)^2; b) (x - 3)(x + 3) - (x - 3)^2

A/ (1+2x) + 2(1+2x) (x-1) + (x-1)^2
B/ (x-3) (x+3) - (x-3)^2
C/ (x-1)^2 (x+2) - (x-2) (x^2+2x+4)