因为 (2 - 1) =1,把这个等于1的形式和你给出的多项式相乘,结果不变:
(2 - 1) ×你式子的左端=(2 - 1) (2+1)(2²+1)(2⁴+1)······(2^128+1)
= (2² - 1) (2²+1)(2⁴+1)······(2^128+1)
= (2⁴-1)(2⁴+1)······(2^128+1)
=......................
==============(2^128-1)(2^128+1)
==================(2^256-1)
结论:(2+1)(2²+1)(2⁴+1)······(2^128+1) = 2^256 - 1