问题 解答题
计算(1+
1
2
+
1
4
)×(
1
2
+
1
4
+
1
6
)-(1+
1
2
+
1
4
+
1
6
)×(
1
2
+
1
4
答案

1
2
+
1
4
=a,
1
2
+
1
4
+
1
6
=b,则:

(1+

1
2
+
1
4
)×(
1
2
+
1
4
+
1
6
)-(1+
1
2
+
1
4
+
1
6
)×(
1
2
+
1
4
),

=(1+a)×b-(1+b)×a,

=b+ab-a-ab,

=b-a,

=(

1
2
+
1
4
+
1
6
)-(
1
2
+
1
4
),

=

1
6

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