x^2
+
____________________
+
y^2
=
(
____________________
+
y
)
^2
a^2
-
2a
+
____________________
=
(
a
+
____________________
)
____________________
____________________
+
____________________
+
1
=
(
2x
+
1
)
^2
____________________
-
____________________
=
(
a
+
4
)
(
a
-
4
)
