5/6-1/12-9/20+11/30-1/42简便运算快,我急用,好的给附加,_数学解答

5/6-1/12-9/20+11/30-1/42简便运算
快,我急用,好的给附加,

人气：282 ℃　时间：2019-10-11 21:10:15

解答

5/6-1/12-9/20+11/30-1/42
=1/2+1/3-(1/3-1/4)-(1/4+1/5)+(1/5+1/6)-(1/6-1/7)
=1/2+1/3-1/3+1/4-1/4-1/5+1/5+1/6-1/6-1/7
=1/2-1/7
=(7-2)/14
=5/14