Question

1/1*3+1/3*5+1/5*7+.+1/49*51怎么计算

Answer 1

1/1*3+1/3*5+1/5*7+.+1/49*51

=(1-1/3)*1/2+(1/3-1/5)*1/2+(1/5-1/7)*1/2+...+(1/49-1/51)*1/2

=(1-1/51)*1/2

=50/51*1/2

=25/51