19/20+29/30+41/42+55/56+71/72= 简便方法做
问题描述:
19/20+29/30+41/42+55/56+71/72= 简便方法做
答
19/20+29/30+41/42+55/56+71/72=1-1/20+1-1/30+1-1/42+1-1/56+1-1/72=5-(1/20+1/30+1/42+1/56+1/72)=5-(1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9)=5-(1/4-1/9)=5-5/36=4又29/36