42956658
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/08/29 01:08:38
256317856
![](http://img.wesiedu.com/upload/6/32/6329260dde4abc85a81880c1c63d4b75.jpg)
![](http://img.wesiedu.com/upload/6/32/6329260dde4abc85a81880c1c63d4b75.jpg)
解题思路: 解决这个问题的关键之处在于认真审题,仔细观察和分析题干中的已知条件和所给的分数的加减混合运算的算式.根据分数的加减混合运算的解题方法,据此计算求解。
解题过程:
3/4 +5/6 - 7/8
=18/24 +20/24 -21/24
=38/24 -21/24
=17/24
3 - 7/11 -4 /11
=3-(7/11 +4/11)
=3-1
=2
8/11 +9/13+3/11 +2/13
=(8/11 + 3/11)+(9/13 +2/13)
=1+ 11/13
=1(11/13)
7/12 -4 /7 +5/12 -3/7
=(7/12 +5/12)-(4/7 +3/7)
=1-1
=0
4/5 -(5/7 -1/2)
=4/5 -3/14
=41/70
5/7-(1/2 +1/8)
=5/7 -5/8
=5/56
解题过程:
3/4 +5/6 - 7/8
=18/24 +20/24 -21/24
=38/24 -21/24
=17/24
3 - 7/11 -4 /11
=3-(7/11 +4/11)
=3-1
=2
8/11 +9/13+3/11 +2/13
=(8/11 + 3/11)+(9/13 +2/13)
=1+ 11/13
=1(11/13)
7/12 -4 /7 +5/12 -3/7
=(7/12 +5/12)-(4/7 +3/7)
=1-1
=0
4/5 -(5/7 -1/2)
=4/5 -3/14
=41/70
5/7-(1/2 +1/8)
=5/7 -5/8
=5/56