解方程. 2x-2/3=1/3 x-(1/4+1/5)=1/20.

问题描述:

解方程.
2x-

2
3
=
1
3

x-(
1
4
+
1
5
)=
1
20


(1)2x-

2
3
=
1
3

  2x-
2
3
+
2
3
=
1
3
+
2
3

        2x=1,
     2x÷2=1÷2,
         x=0.5;
(2)x-(
1
4
+
1
5
)=
1
20

            x-
9
20
=
1
20

        x-
9
20
+
9
20
=
1
20
+
9
20

                x=
1
2