1/2=1/1-1/2;1/6=1/2-1/3;1/12=1/3-1/4.根据以上规律,计算:1/2+1/6+1/12+20/1+30/1+1/42+1/56

问题描述:

1/2=1/1-1/2;1/6=1/2-1/3;1/12=1/3-1/4.根据以上规律,计算:1/2+1/6+1/12+20/1+30/1+1/42+1/56
1/2=1/1-1/2;1/6=1/2-1/3;1/12=1/3-1/4.根据以上规律,计算:1/2+1/6+1/12+1/20+1/30+1/42+1/56

1/2+1/6+1/12+1/20+1/30+1/42+1/56
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8
=1-1/8
=7/8