100-1/100-2/100-3/100-……-100/100如何简算

问题描述:

100-1/100-2/100-3/100-……-100/100如何简算

100-1/100-2/100-3/100-……-100/10
=100-100/100-(1/100+2/100+3/100-……+99/100)
=99-(1+2+3+···99)/100
=99-(1+99)×99÷2÷100
=99-49·5
=49·5乘以99除以2不太明白,麻烦解释一下,谢谢这是一个数列的算法:比如1+2+3+4+5+6=(1+6)+(2+5)+(3+4)=7+7+7=(1+6)×6÷2=21同样的道理1+2+3+···99=(1+99)×99÷2