(1)x-
1
5 x=
3
8 ,
4
5 x=
3
8 ,
4
5 x×
5
4 =
3
8 ×
5
4 ,
x=
15
32 ;
(2)x×
4
7 ×
7
12 =3 ,
1
3 x=3,
1
3 x×3=3×3,
x=9;
(3)x+
3
5 x=
3
5 ×
2
15 ,
8
5 x=
2
25 ,
8
5 x×
5
8 =
2
25 ×
5
8 ,
x=
1
20 .
(1)x-
1
5 x=
3
8 ,
4
5 x=
3
8 ,
4
5 x×
5
4 =
3
8 ×
5
4 ,
x=
15
32 ;
(2)x×
4
7 ×
7
12 =3 ,
1
3 x=3,
1
3 x×3=3×3,
x=9;
(3)x+
3
5 x=
3
5 ×
2
15 ,
8
5 x=
2
25 ,
8
5 x×
5
8 =
2
25 ×
5
8 ,
x=
1
20 .