1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9.+100+100等于几?
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/05 12:46:46
![1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9.+100+100等于几?](/uploads/image/z/1658006-62-6.jpg?t=1%2B1%2B2%2B2%2B3%2B3%2B4%2B4%2B5%2B5%2B6%2B6%2B7%2B7%2B8%2B8%2B9%2B9.%2B100%2B100%E7%AD%89%E4%BA%8E%E5%87%A0%3F)
1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9.+100+100等于几?
1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9.+100+100等于几?
1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9.+100+100等于几?
1+2+3+.+100=(1+100)*100/2=5050
所以1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9.+100+100=2*5050=10100
(1+100)*100=10100
1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9...........+100+100
=2*(1+2+..+100)
=2*100*(1+100)/2
=10100
2*(1+2+3+.......+100)=2*5050=10100