用递等式计算:① 5 6 - 1 4 + 1 3 &...


用递等式计算:① 5 6 - 1 4 + 1 3 ② 23 28 +( 13 14 + 2 7 ) ③7-( 3 4 - 2 5 )
(1)
5
6
-
1
4
+
1
3

=
7
12
+
1
3
,穗返
=
11
12


(2)
23
28
+(
13
14
+
2
7
)洞碰
=
23
28
+
17
14

=
57
28


(3)7-(
3
4
-
2
5

=7-
7
20
,猜颤饥
=6
13
20