(1)x-
=5 6
2 15
x-
+5 6
=5 6
+2 15
5 6
x=
;29 30
(2)x-(
-5 6
)=1 5
8 15
x-
=19 30
8 15
x-
+19 30
=19 30
+8 15
19 30
x=
;7 6
(3)
-2x=4 5
1 4
-2x+2x=4 5
+2x1 4
+2x=1 4
4 5
+2x-1 4
=1 4
-4 5
1 4
2x=
11 20
2x÷2=
÷211 20
x=