Question

1x3分之1＋3x5分之一＋5x7分之一＋……＋15x17分之一1

Answer 1

1x1/3+1/(3x5)+1/(5x7)+...+1/(15x17)

=(1-1/3)/2+(1/3-1/5)/2+(1/5-1/7)/2+...+(1/15-1/17)/2

=(1-1/3+1/3-1/5+1/5-1/7+...+1/15-1/17)/2

=(1-1/17)/2

=8/17