(51+52.......+99+100)-(1+2+3+......+49+50)怎么做

用前一个数加后一个数也就和、 (51+52.......+99+100)-(1+2+3+......+49+50) =(50+1+50+2+50+3...+50+50)-(1+2+3+...+49+50) =50*50+1+2+3+...+50-(1+2+3+...+49+50) =2500