用简便方法计算.5-37-4716+38+5859-(56-712)1112+58+18+11279-(13+49)320+815+1720.-数学

题文

用简便方法计算.
5-
3
7
-
4
7
1
6
+
3
8
+
5
8
5
9
-(
5
6
-
7
12
)
11
12
+
5
8
+
1
8
+
1
12
7
9
-(
1
3
+
4
9
3
20
+
8
15
+
17
20
题型:解答题  难度:中档

答案

(1)5-
3
7
-
4
7

=5-(
3
7
+
4
7
),
=5-1,
=4;

(2)
1
6
+
3
8
+
5
8

=
1
6
+(
3
8
+
5
8