题目内容
计算下面各题,怎样算简便就怎样算.
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分析:(1)先算小括号里面的减法,再算括号外的减法;
(2)按照从左到右的顺序计算;
(3)先算小括号里面的加法,再算括号外的减法;
(4)(6)根据减法的性质简算;
(5)运用乘法交换律简算.
(2)按照从左到右的顺序计算;
(3)先算小括号里面的加法,再算括号外的减法;
(4)(6)根据减法的性质简算;
(5)运用乘法交换律简算.
解答:解:(1)
-(
-
),
=
-
,
=
;
(2)
+
-
,
=
-
,
=
;
(3)
-(
+
),
=
-
,
=
;
(4)
-
-
,
=
-(
+
),
=
-
,
=
;
(5)
+
+
,
=(
+
)+
,
=1+
,
=1
;
(6)
-(
+
),
=
-
-
,
=
-
,
=
.
| 3 |
| 5 |
| 1 |
| 2 |
| 1 |
| 4 |
=
| 3 |
| 5 |
| 1 |
| 4 |
=
| 7 |
| 20 |
(2)
| 3 |
| 10 |
| 1 |
| 5 |
| 1 |
| 3 |
=
| 1 |
| 2 |
| 1 |
| 3 |
=
| 1 |
| 6 |
(3)
| 8 |
| 9 |
| 1 |
| 6 |
| 1 |
| 3 |
=
| 8 |
| 9 |
| 1 |
| 2 |
=
| 7 |
| 18 |
(4)
| 7 |
| 10 |
| 1 |
| 8 |
| 3 |
| 8 |
=
| 7 |
| 10 |
| 1 |
| 8 |
| 3 |
| 8 |
=
| 7 |
| 10 |
| 1 |
| 2 |
=
| 1 |
| 5 |
(5)
| 3 |
| 7 |
| 9 |
| 10 |
| 4 |
| 7 |
=(
| 3 |
| 7 |
| 4 |
| 7 |
| 9 |
| 10 |
=1+
| 9 |
| 10 |
=1
| 9 |
| 10 |
(6)
| 5 |
| 9 |
| 2 |
| 9 |
| 1 |
| 6 |
=
| 5 |
| 9 |
| 2 |
| 9 |
| 1 |
| 6 |
=
| 1 |
| 3 |
| 1 |
| 6 |
=
| 1 |
| 6 |
点评:本题考查了基本的分数加减混合运算,要注意分析数据,灵活运用运算定律简算.
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