问题 解答题
解方程.
5x-3×
7
10
=
7
5

4
5
+
1
2
x=
9
10

2x-45%=5
11
20
答案

(1)5x-3×

7
10
=
7
5

5x-

21
10
=
7
5

5x-

21
10
+
21
10
=
7
5
+
21
10

5x=

35
10

5x÷5=

35
10
÷5,

x=

35
10
×
1
5

x=

7
10

(2)

4
5
+
1
2
x=
9
10

4
5
+
1
2
x-
4
5
=
9
10
-
4
5

1
2
x=
1
10

1
2
x×2=
1
10
×2,

x=

1
5

(3)2x-45%=5

11
20

2x-45%+45%=5

11
20
+45%,

2x=5.55+0.45,

2x=6,

2x÷2=6÷2,

x=3.

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