(x-1)(x^99+x^98+x^97+...+1)
=x(x^99+x^98+x^97+...+1)-1*(x^99+x^98+x^97+...+1)
=x^100+x^99+x^98+...+x-x^99-x^98-x^97-...-1
=x^100-1
当x=2,原式=2^100-1