题目内容
(11
+9
)÷(
+
).
| 2 |
| 9 |
| 2 |
| 11 |
| 2 |
| 9 |
| 2 |
| 11 |
分析:11
+9
=
+
=101×(
+
),
+
=2×(
+
),然后再根据乘法交换律和结合律以及除法的性质进行简算.
| 2 |
| 9 |
| 2 |
| 9 |
| 101 |
| 9 |
| 101 |
| 11 |
| 1 |
| 9 |
| 1 |
| 11 |
| 2 |
| 9 |
| 2 |
| 9 |
| 1 |
| 9 |
| 1 |
| 11 |
解答:解:(11
+9
)÷(
+
),
=(
+
)÷(
+
)
=101×(
+
)÷[2×(
+
)],
=101×(
+
)÷2÷(
+
),
=(101÷2)×[(
+
)÷(
+
)],
=50.5×1,
=50.5.
| 2 |
| 9 |
| 2 |
| 11 |
| 2 |
| 9 |
| 2 |
| 11 |
=(
| 101 |
| 9 |
| 101 |
| 11 |
| 2 |
| 9 |
| 2 |
| 9 |
=101×(
| 1 |
| 9 |
| 1 |
| 11 |
| 1 |
| 9 |
| 1 |
| 11 |
=101×(
| 1 |
| 9 |
| 1 |
| 11 |
| 1 |
| 9 |
| 1 |
| 11 |
=(101÷2)×[(
| 1 |
| 9 |
| 1 |
| 11 |
| 1 |
| 9 |
| 1 |
| 11 |
=50.5×1,
=50.5.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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