(3
- 1
) + (6
- 1
) = (
-
+ (
-
) =
-
) + (
-
) =
+
=
(2
+
) - (1
-
) = (
+
) – (
-
) = (
+
) – (
-
) =
-
=
(10 -
) - (5
- 3
) = (10 -
) – (
-
) = (
-
) – (
-
) =
-
=
-
=
(2
+ 3
) – (1
+ 3
) = (
+
) – (
+
) = (
+
) – (
+
) =
-
=
-
=