问题 解答题
计算,能简则简.
1
7
+
7
8
×
5
7
+
3
8

1
4
×
3
5
+
1
4
×
2
5

2-
6
13
÷
9
26
-
2
3

1
5
÷[(
2
3
+
1
5
)×
1
13
].
答案

(1)

1
7
+
7
8
×
5
7
+
3
8

=

1
7
+
5
8
+
3
8

=

1
7
+(
5
8
+
3
8

=

1
7
+1

=1

1
7

(2)

1
4
×
3
5
+
1
4
×
2
5

=

1
4
×(
3
5
+
2
5

=

1
4
×1

=

1
4

(3)2-

6
13
÷
9
26
-
2
3

=2-

4
3
-
2
3

=2-(

4
3
+
2
3

=2-2

=0;

(4)

1
5
÷[(
2
3
+
1
5
)×
1
13
]

=

1
5
÷[
13
15
×
1
13
]

=

1
5
÷
1
15

=3.

单项选择题
单项选择题