(1)x-
5
6 =
1
9 ,
x-
5
6 +
5
6 =
1
9 +
5
6 ,
x=
17
18 ;
(2)
2
7 +x=
3
4 ,
2
7 +x-
2
7 =
3
4 -
2
7 ,
x=
13
28 ;
(3)3x-x=1.8,
2x=1.8,
2x÷2=1.8÷2,
x=0.9;
(4)
5
9 -x=
1
6 ,
5
9 -x+x=
1
6 +x,
1
6 +x-
1
6 =
5
9 -
1
6 ,
x=
7
18 .
(1)x-
5
6 =
1
9 ,
x-
5
6 +
5
6 =
1
9 +
5
6 ,
x=
17
18 ;
(2)
2
7 +x=
3
4 ,
2
7 +x-
2
7 =
3
4 -
2
7 ,
x=
13
28 ;
(3)3x-x=1.8,
2x=1.8,
2x÷2=1.8÷2,
x=0.9;
(4)
5
9 -x=
1
6 ,
5
9 -x+x=
1
6 +x,
1
6 +x-
1
6 =
5
9 -
1
6 ,
x=
7
18 .