(
2
+
i
)
*
(
2
-
i
)
=
____________________
+
____________________
(
2
+
i
)
*
(
-
2
+
i
)
=
-
____________________
+
____________________
(
1
-
i
)
*
(
1
-
i
)
=
____________________
-
____________________
(
3
-
2i
)
*
(
-
1
-
i
)
=
-
____________________
-
____________________
(
1
+
2i
)
*
(
2
+
i
)
=
____________________
+
____________________
(
3
-
2i
)
*
(
-
1
-
i
)
*
(
4
+
5i
)
=
____________________
-
____________________
(
8
-
2i
)
*
(
(
-
1
-
i
)
+
(
2
+
3i
)
)
=
____________________
+
____________________
3
*
(
2
+
i
)
*
(
7
+
2i
)
=
____________________
+
____________________