1/2x3X4十1/3X4x5十1/4X5X6……十1/8X9X10等于多少最好给个详细答案谢谢
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/30 08:45:28
![1/2x3X4十1/3X4x5十1/4X5X6……十1/8X9X10等于多少最好给个详细答案谢谢](/uploads/image/z/102241-1-1.jpg?t=1%2F2x3X4%E5%8D%811%2F3X4x5%E5%8D%811%2F4X5X6%E2%80%A6%E2%80%A6%E5%8D%811%2F8X9X10%E7%AD%89%E4%BA%8E%E5%A4%9A%E5%B0%91%E6%9C%80%E5%A5%BD%E7%BB%99%E4%B8%AA%E8%AF%A6%E7%BB%86%E7%AD%94%E6%A1%88%E8%B0%A2%E8%B0%A2)
1/2x3X4十1/3X4x5十1/4X5X6……十1/8X9X10等于多少最好给个详细答案谢谢
1/2x3X4十1/3X4x5十1/4X5X6……十1/8X9X10等于多少最好给个详细答案谢谢
1/2x3X4十1/3X4x5十1/4X5X6……十1/8X9X10等于多少最好给个详细答案谢谢
1/2x3X4=(1/2X3-1/3X4)X1/2
1/3X4x5=(1/3X4-1/4X5)X1/2
.1/8X9X10=(1/8X9-1/9X10)X1/2
上述各式相加得:
1/2x3X4十1/3X4x5十1/4X5X6……十1/8X9X10
=(1/2X3-1/3X4+1/3X4-1/4X5+.+1/8X9-1/9X10)X1/2
=(1/2X3-1/9X10)X1/2
=(1/6-1/90)X1/2
=(15/90-1/90)X1/2
=14/90 X 1/2
=7/90