Rút gọn biểu thức: a) (x - 2y + 3z ).(x + 2y - 3z); b) (a + b + c)^2 - (b + c)^2 - c^2; c) (2 + 1).(2^2 + 1).(2^4 + 1).(2^8 + 1).(2^16 + 1)

1. rút gọn biểu thức:
a) (x - 2y + 3z ).(x+ 2y-3z)
b)(a+b+c)^2 - (b+c)^2- c^2
c)(2+1).(2^2+1).(2^4+1).(2^8+1).(2^16+1)
d) (3+1).(3^2+1).(3^4+1).(3^8+1).(3^16+1).(3^32+1)
e)(2a-3b)^2+(2a-b).(4a^2+2ab+b^2)-(a-b)^3
f)(x^4-5x^2+25).(x^2+5)-(2+x^2)^3+3.(1+x^2)^2