(1/2+1/4+1/6+1/10+1/12+1/60)/(1+1/3+1/5+1/10+1/15+1/30)

(1/2+1/4+1/6+1/10+1/12+1/60)/(1+1/3+1/5+1/10+1/15+1/30) (1+1/3+1/5+1/10+1/15+1/30)/(1/2+1/4+1/6+1/12+1/20+1/60)(用简算) (1+1/3+1/5+1/10+1/15+1/30)/(1/2+1/4+1/6+1/12+1/20+1/60)=R 简算:（1+1/3+1/5+1/10+1/15+1/30）÷（1/2+1/4+1/6+1/12+1/20+1/60）＝? （1+1/3+1/5+1/10+1/15+1/30）÷（1/2+1/4+1/6+1/12+1/20+1/60） 2/1 3/1 4/1 5/1 6/1 8/1 10/1 12/1 15/1 20/1 1 1 1 1 2 1 1 3 3 1 1 4 6 4 1 1 5 10 10 5 1 1 6 15 20 15 6 1 (1/2-1/3)+(1/4-1/5)+(1/7-1/10)+(1/14-1/15)+(1/28-1/30) (1/2-1/3)+(1/4-1/5)+(1/7-1/10)+(1/14-1/15)+(1/28-1/30)) (1+3分之1+5分之1+10分之1+15分之1+30分之1)÷(2分之1+4分之1+6分之1+12分之1+60分之1) (1/2+1/3+1/4+1/5+1/6+1/7+1/8+1/9+1/10+1/11+1/12+1/13+1/14+1/ 1 1 -1 1 -2 1 1 -3 3 -1 1 -4 6 -4 1 1 -5 10 x 5 -1 1 -6 15 -