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9
2
+
9
7
=
9
2
×
9
7
    
8
3
+
8
5
=
8
3
×
8
5
     
11
4
+
11
7
=
11
4
×
11
7
    
7
3
+
7
4
=
(   )
(   )
×
(   )
(   )

请你照上面的例子也写出两个a+b=a?b的算式.
5
2
+
5
3
=
5
2
×
5
3
5
2
+
5
3
=
5
2
×
5
3
11
2
+
11
9
=
11
2
×
11
9
11
2
+
11
9
=
11
2
×
11
9
分析:观察给出的式子,当两个分数的分子相同,并且等于两个分数的分母的和时,这两个分数的和等于这两个分数的乘积.
解答:解:由题意得出:
7
3
+
7
4
=
7
3
×
7
4

例如:
5
2
+
5
3
=
5
2
×
5
3
11
2
+
11
9
=
11
2
×
11
9

故答案为:
7
3
7
4
5
2
+
5
3
=
5
2
×
5
3
11
2
+
11
9
=
11
2
×
11
9
点评:关键是根据给出的式子的各个数的特点,找出规律,再由规律解决问题.
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