1/1×4+1/4×7+1/7×10+1/10×13+1/13×16=?请把过程写清楚!

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/11 01:21:52

1/1×4+1/4×7+1/7×10+1/10×13+1/13×16=?请把过程写清楚!
1/1×4+1/4×7+1/7×10+1/10×13+1/13×16=?
请把过程写清楚!

1/1×4+1/4×7+1/7×10+1/10×13+1/13×16=?请把过程写清楚!
1/1*4+1/4*7+1/7*10+1/10*13+1/13*16
=1/3*(1-1/4)+1/3*(1/4-1/7)+1/3*(1/7-1/10)+1/3*(1/10-1/13)+1/3*(1/13-1/16)
=1/3*(1-1/4+1/4-1/7+1/7-1/10+1/10-1/13+1/13-1/16)
=1/3*(1-1/16)
=1/3*15/16
=5/16

1/1×4+1/4×7+1/7×10+1/10×13+1/13×16
=1/3*(1-1/4+1/4-1/7+.....+1/13-1/16)
=5/16

不会!

ce,250