x^3-3x-2
=x^3-x-2x-2
=x(x^2-1)-2(x+1)
=x(x-1)(x+1)-2(x+1)
=(x+1)[x(x-1)-2)
=(x+1)(x^2-x-2)
=(x+1)(x-2)(x+1)
=(x-2)(x+1)^2
63=64-1=2^6-1
65=64+1=2^6+1
(2^48-1)
=(2^24+1)(2^24-1)
=(2^24+1)(2^12+1)(2^12-1)
=(2^24+1)(2^12+1)(2^6+1)(2^6-1)
(2^-48-1)/63=(2^24+1)(2^12+1)(2^6+1)
(2^-48-1)/65=(2^24+1)(2^12+1)(2^6-1)
2^48-1可以被63和65整除