问题 解答题
巧解密码.
3
4
1
6
=18
1-
4
15
x=
1
5
75÷
5
6
-
8
9
x=0
x+
x
5
=240.
答案

(1)

3
4
x÷
1
6
=18

3
4
x÷
1
6
×
1
6
=18×
1
6

3
4
x÷
3
4
=3÷
3
4

x=4;

(2)1-

4
15
x=
1
5

1-

4
15
x+
5
15
x=
1
5
+
4
15
x

1=

1
5
+
4
15
x

1
5
+
4
15
x-
1
5
=1-
1
5

4
15
x=
4
5

4
15
x÷
4
15
=
4
5
÷
4
15

x=3

(3)75÷

5
6
-
8
9
x=0

90-

8
9
x=0

90-

8
9
x+
8
9
x=0+
8
9
x

8
9
x=90

8
9
8
9
=90÷
8
9

x=

405
4

(4)x+

x
5
=240

1.2x=240

1.2x÷1.2=240÷1.2

x=200.

判断题
单项选择题