请数学高手来做

学习帮助  |  教育科学

分享:
2012-12-29

2012-12-29最佳答案

1/(1*4)= (1/1-1/4)/31/(4*7)= (1/4-1/7)/31/(7*10)= (1/7-1/10)/31/(10*13)= (1/10-1/13)/3所以1/1*4 +1/4*7 +1/7*10 +1/10*13= (1/1-1/4)/3+(1/4-1/7)/3+(1/7-1/10)/3+ (1/10-1/13)/3 =(1-1/13)/3 = 4/13

其它1条答案


4/13

2012-12-29