50²-49²+48²-47²+…+2²-1=

来源：学生作业学帮网编辑：学帮网时间：2024/05/31 16:00:04

50²-49²+48²-47²+…+2²-1
=(50+49)*(50-49)+(48+47)*(48-47)+…+(2+1)*(2-1)
=50+49+48+47+…+2+1
=(50+1)*50/2
=1275