(1)8x=
16
19 ,
8x÷8=
16
19 ÷8,
x=
2
19 ;
(2)x-25%x=
15
28 ,
(1-25%)x=
15
28 ,
3
4 x=
15
28 ,
3
4 x×
4
3 =
15
28 ×
4
3 ,
x=
5
7 ;
(3)
7
8 x+
1
8 =2,
7
8 x+
1
8 -
1
8 =2-
1
8 ,
7
8 x=
15
8 ,
7
8 x×
8
7 =
15
8 ×
8
7 ,
x=
15
7 .
(1)8x=
16
19 ,
8x÷8=
16
19 ÷8,
x=
2
19 ;
(2)x-25%x=
15
28 ,
(1-25%)x=
15
28 ,
3
4 x=
15
28 ,
3
4 x×
4
3 =
15
28 ×
4
3 ,
x=
5
7 ;
(3)
7
8 x+
1
8 =2,
7
8 x+
1
8 -
1
8 =2-
1
8 ,
7
8 x=
15
8 ,
7
8 x×
8
7 =
15
8 ×
8
7 ,
x=
15
7 .