-1/2+-1/6+-1/12+.-1/132

题目

-1/2+-1/6+-1/12+.-1/132
负二分之一加负六分之一加负十二分之一,然后按规律加到负一百三十二分之一.

答案

=-(1/2+1/6+1/12+……+1/132)
=-(1/1*2+1/2*3+1/3*4+……+1/11*12)
=-(1-1/2+1/2-1/3+1/3-1/4+……+1/11-1/12)
=-(1-1/12)
=-11/12