好急呀~
1)(+1/3)+(-2/5)
2)(-1/2)+(+2)-(-3/4)
3)+3-[(1/2-1/3)-(+1/4)]
4)-(-1)-(+1/2)-[-(1/4-2/5)]
急`中1有向數`(15點)
2008-09-23 3:41 am
回答 (2)
2008-09-23 4:02 am
✔ 最佳答案
1)(+1/3)+(-2/5)=1/3-2/5
=5/15-6/15
=-1/15
2)(-1/2)+(+2)-(-3/4)
=-1/2+2+3/4
=2+3/4-1/2
=2+3/4-2/4
=2/1/4
3)+3-[(1/2-1/3)-(+1/4)]
=3-(6/12-4/12-3/12)
=3-(-1/12)
=36/12+1/12
=37/12
=3/1/12
4)-(-1)-(+1/2)-[-(1/4-2/5)]
=1-1/2+(5/20-8/20)
=1/2+(-3/20)
=1/2-3/20
=10/20-3/20
=7/20
參考: 自己:]
2008-09-23 3:58 am
1)(+1/3)+(-2/5)
=1/3-2/5
= -1/15
2)(-1/2)+(+2)-(-3/4)
= -1/2+2+3/4
=
=9/4
3)+3-[(1/2-1/3)-(+1/4)]
=3-1/2+1/3+1/4
=37/12
4)-(-1)-(+1/2)-[-(1/4-2/5)]
=1-1/2+1/4-2/5
=7/20
=1/3-2/5
= -1/15
2)(-1/2)+(+2)-(-3/4)
= -1/2+2+3/4
=
=9/4
3)+3-[(1/2-1/3)-(+1/4)]
=3-1/2+1/3+1/4
=37/12
4)-(-1)-(+1/2)-[-(1/4-2/5)]
=1-1/2+1/4-2/5
=7/20
收錄日期: 2021-04-23 20:35:07
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080922000051KK01776