(1²+3²+5²+……+99²)-(2²+4²+6²+……+100²)
问题描述:
(1²+3²+5²+……+99²)-(2²+4²+6²+……+100²)
答
=1²-2²+3²-4²+5²-6²+……+99²-100²=(1-2)(1+2)+(3-4)(3+4)+(5-6)(5+6)+……+(99-100)(99+100)=-1-2-3-4-5-6-……-99-100=-5050