问题 解答题
解方程:
X-
4
5
=
3
8
2X-5.8=6.6 X-(
5
21
+
3
7
)=
2
3
4
5
-3X=
1
4
答案

(1)x-

4
5
=
3
8

x-

4
5
+
4
5
=
3
8
+
4
5

x=

47
40

(2)2X-5.8=6.6,

2X-5.8+5.8=6.6+5.8,

2x=12.4,

2x÷2=12.4÷2,

x=6.2;

(3)x-(

5
21
+
3
7
)=
2
3

x-

2
3
=
2
3

x-

2
3
+
2
3
=
2
3
+
2
3

x=

4
3

(4)

4
5
-3x=
1
4

4
5
-3x+3x=
1
4
+3x,

3x+

1
4
=
4
5

3x+

1
4
-
1
4
=
4
5
-
1
4

3x=

11
20

3x÷3=

11
20
÷3,

x=

11
60

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