题目内容
用简便方法计算
×
+
×
(
-
)×3649×
×30．
| 14 |
| 5 |
| 5 |
| 9 |
| 5 |
| 9 |
| 31 |
| 5 |
(
| 5 |
| 9 |
| 4 |
| 18 |
| 49 |
| 50 |
| 28 |
| 29 |
（1）
| 14 |
| 5 |
| 5 |
| 9 |
| 5 |
| 9 |
| 31 |
| 5 |
=（
| 14 |
| 5 |
| 31 |
| 5 |
| 5 |
| 9 |
=9×
| 5 |
| 9 |
=5；
（2）(
| 5 |
| 9 |
| 4 |
| 18 |
=
| 5 |
| 9 |
| 4 |
| 18 |
=20-8，
=12；
（3）49×
| 49 |
| 50 |
=（50-1）×
| 49 |
| 50 |
=50×
| 49 |
| 50 |
| 49 |
| 50 |
=49-
| 49 |
| 50 |
=48
| 1 |
| 50 |
（4）
| 28 |
| 29 |
=
| 28 |
| 29 |
=
| 28 |
| 29 |
| 28 |
| 29 |
=28+
| 28 |
| 29 |
=28
| 28 |
| 29 |
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