1+三分之一+六分之一+十分之一+十五分之一+二十一分之一+二十八分之一+三十六分之一+四十五分之一是多少?

1+三分之一+六分之一+十分之一+十五分之一+二十一分之一+二十八分之一+三十六分之一+四十五分之一1+1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45=1+1/3+1/2-1/3+1/10+1/15+1/21+1/28+1/36+1/45=1+1/2+1/10+1/15+1/21+1/28+1/36+1/45=1+1/2+1/3*(1/2-1/5)+1/2*(1/3-1/5)+1/4*(1/3-1/7)+1/3*(1/4-1/7)+1/5*(1/4-1/9)+1/4*(1/5-1/9)=1+1/2+1/3*1/2-1/3*1/5+1/2*1/3-1/2*1/5+1/4*1/3-1/4*1/7+1/3*1/4-1/3*1/7+1/5*1/4-1/5*1/9+1/4*1/5-1/4*1/9=1+1/2+1/3*1/2+1/2*1/3-1/3*1/5-1/2*1/5+1/4*1/3+1/3*1/4-1/4*1/7-1/3*1/7+1/5*1/4+1/4*1/5-1/5*1/9-1/4*1/9=1+1/2+1/3-1/3*1/5-1/2*1/5+1/6-1/4*1/7-1/3*1/7+1/10-1/5*1/9-1/4*1/9=1+1/2+1/3+1/6-1/3*1/5-1/2*1/5-1/4*1/7-1/3*1/7+1/10-1/5*1/9-1/4*1/9=1+1-1/3*1/5-1/2*1/5-1/4*1/7-1/3*1/7+1/10-1/5*1/9-1/4*1/9=2-1/3*1/5-1/2*1/5-1/4*1/7-1/3*1/7+1/10-1/5*1/9-1/4*1/9=2-(1/3+1/2)*1/5-(1/4+1/3)*1/7+1/10-(1/5+1/4)*1/9=2-5/6*1/5-7/12*1/7+1/10-(9/20)*1/9=2-1/6-1/12+1/10-1/20=2-1/6-1/12+1/10-1/20=2-1/2+1/3-1/3+1/4-1/4+1/5+1/10=2-1/2+1/5+1/10=1+1-1/2+1/5+1/10=1+1/2+1/5+1/10=1+5/10+2/10+1/10=1+8/10=1+4/5=9/5