498+9870÷35420.5-294÷2.8×2.1(23-25)÷(18+512)23÷(34+112×45)35÷[(14+27)×720].-数学

题文

498+9870÷35
420.5-294÷2.8×2.1
2
3
-
2
5
)÷(
1
8
+
5
12

2
3
÷(
3
4
+
1
12
×
4
5

3
5
÷[(
1
4
+
2
7
)×
7
20
].
题型:解答题  难度:中档

答案

(1)498+9870÷35
=498+282,
=780;

(2)420.5-294÷2.8×2.1
=420.5-220.5,
=200;

(3)(
2
3
-
2
5
)÷(
1
8
+
5
12

=
4
15
÷
13
24

=
32
65


(4)
2
3
÷(
3
4
+
1
12
×
4
5

=
2
3
÷(
3
4
+
1
15
),
=
2
3
÷
49
60

=