1/(1*2)+1/(2*3)+1(3*4)+1/(3*4)+1/(4*5)+1/(5*6).1/(99*100)

问题描述:

1/(1*2)+1/(2*3)+1(3*4)+1/(3*4)+1/(4*5)+1/(5*6).1/(99*100)

1/(1*2)+1/(2*3)+1(3*4)+1/(3*4)+1/(4*5)+1/(5*6).1/(99*100)
=1-1/2+1/2-1/3+.+1/99-1/100
=1-1/100
=99/100