题目内容
计算:
|
|
|
分析:(1)运用乘法分配律的逆运算简算;
(2)先算括号内的,原式变为
÷
×
,把除法改为乘法,约分即可;
(3)先算括号内的,再算括号外的.
(2)先算括号内的,原式变为
| 5 |
| 6 |
| 11 |
| 20 |
| 1 |
| 5 |
(3)先算括号内的,再算括号外的.
解答:解:(1)
×
+40%×
,
=(
+40%)×
,
=
×
,
=
;
(2)
÷(1-
)×
,
=
÷
×
,
=
×
×
,
=
;
(3)
÷(
+
),
=
÷
,
=
×
,
=
.
| 2 |
| 5 |
| 6 |
| 11 |
| 5 |
| 11 |
=(
| 2 |
| 5 |
| 5 |
| 11 |
=
| 4 |
| 5 |
| 5 |
| 11 |
=
| 4 |
| 11 |
(2)
| 5 |
| 6 |
| 9 |
| 20 |
| 1 |
| 5 |
=
| 5 |
| 6 |
| 11 |
| 20 |
| 1 |
| 5 |
=
| 5 |
| 6 |
| 20 |
| 11 |
| 1 |
| 5 |
=
| 10 |
| 33 |
(3)
| 9 |
| 16 |
| 3 |
| 8 |
| 1 |
| 16 |
=
| 9 |
| 16 |
| 7 |
| 16 |
=
| 9 |
| 16 |
| 16 |
| 7 |
=
| 9 |
| 7 |
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
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