Question

1/(10*11)+1/(11*12)+1/(12*13)+......+1/(59*60)?

Answer 1

你好 楼主
原式== 1/10×11＋1/11×12＋1/12×13＋……1/59×60
= 1/10-1/11+1/11-1/12+1/12-1/13+……+1/59-1/60
= 1/10-1/60
= 1/12
=1/12

Answer 2

1/(10*11)+1/(11*12)+1/(12*13)+......+1/(59*60)
=1/10-1/11+1/11-1/12+1/12...+1/59-1/60
=1/10-1/60
=1/12

Answer 3

原式=（1/10-1/11）+（1/11-1/12）+（1/12-1/13）+...+（1/58-1/59）+（1/59-1/60）
=1/10-1/60
=1/12

Answer 4

1/10-1/60=1/12

Answer 5

=1/10-1/11+1/11-1/12+...+1/59-1/60=1/10-1/60=1/12