早教吧 育儿知识 作业答案 考试题库 百科 知识分享

简便运算.(13+14+15)×606715×2.5-212×4715237+359-337+149+147421415÷7.

题目详情
简便运算.
1
3
+
1
4
+
1
5
)×60
6
7
15
×2.5-2
1
2
×4
7
15
2
3
7
+3
5
9
-3
3
7
+1
4
9
+1
4
7
42
14
15
÷7.
▼优质解答
答案和解析
(1)(
1
3
+
1
4
+
1
5
)×60,
=
1
3
×60+
1
4
×60+
1
5
×60,
=20+15+12,
=47;

(2)6
7
15
×2.5-2
1
2
×4
7
15

=(6
7
15
-4
7
15
)×2
1
2

=2×2
1
2

=5;

(3)2
3
7
+3
5
9
-3
3
7
+1
4
9
+1
4
7

=(2+
3
7
)+(3+
5
9
)-(3+
3
7
)+(1+
4
9
)+(1+
4
7
),
=(2+3-3+1+1)+(
3
7
-
3
7
+
4
7
)+(
5
9
+
4
9
),
=4+
4
7
+1,
=5
4
7


(4)42
14
15
÷7,
=(42+
14
15
)×
1
7

=42×
1
7
+
14
15
×
1
7

=6+
2
15

=6
2
15