题目内容
| 1 |
| 5 |
| 1 |
| 45 |
| 1 |
| 117 |
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| 221 |
方法一:
+
+
+
=
+
×
+
×
+
×
,
=
×(1+
)+
×(
+
),
=
+
×
,
=
×(1+
),
=
×
,
=
.
方法二:
+
+
+
,
=4×(
+
+
+
)÷4,
=(
+
+
+
)÷4,
=(1-
+
-
+
-
+
-
)÷4,
=(1-
)÷4,
=
÷4,
=
.
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| 221 |
=
| 1 |
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| 1 |
| 5 |
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| 9 |
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| 9 |
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| 13 |
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| 13 |
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| 17 |
=
| 1 |
| 5 |
| 1 |
| 9 |
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| 13 |
| 1 |
| 9 |
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| 17 |
=
| 2 |
| 9 |
| 2 |
| 9 |
| 1 |
| 17 |
=
| 2 |
| 9 |
| 1 |
| 17 |
=
| 2 |
| 9 |
| 18 |
| 17 |
=
| 4 |
| 17 |
方法二:
| 1 |
| 5 |
| 1 |
| 45 |
| 1 |
| 117 |
| 1 |
| 221 |
=4×(
| 1 |
| 5 |
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| 45 |
| 1 |
| 117 |
| 1 |
| 221 |
=(
| 4 |
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| 4 |
| 45 |
| 4 |
| 117 |
| 4 |
| 221 |
=(1-
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| 1 |
| 5 |
| 1 |
| 9 |
| 1 |
| 9 |
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| 13 |
| 1 |
| 13 |
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=(1-
| 1 |
| 17 |
=
| 16 |
| 17 |
=
| 4 |
| 17 |
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