1
.
(
+
3
)
+
(
+
5
)
=
+
____________________
(
-
4
)
+
(
-
8
)
=
-
____________________
2
.
(
+
12
)
+
(
+
13
)
=
+
____________________
(
-
7
)
+
(
-
16
)
=
-
____________________
3
.
(
+
9
)
+
(
-
4
)
=
+
____________________
(
-
15
)
+
(
+
6
)
=
-
____________________
(
-
9
)
+
(
+
4
)
=
-
____________________
(
+
15
)
+
(
-
6
)
=
+
____________________
4
.
(
+
3
)
+
(
-
1
)
+
(
+
4
)
+
(
-
5
)
+
(
-
9
)
=
(
+
7
)
+
(
-
15
)
=
-
____________________
5
.
(
+
5
)
+
(
-
2
)
+
(
-
6
)
+
(
+
8
)
=
+
____________________
6
.
(
+
3
)
+
(
-
6
)
+
(
+
8
)
=
+
____________________
7
.
(
-
3
)
+
(
+
8
)
=
+
____________________
8
.
(
+
3
)
+
(
+
7
)
=
+
____________________
