Справочник
R.1.
R.1.5. Формулы сокращённого умножения
a
2
–
b
2
= (
a
+
b
)(
a
–
b
)
(
a
+
b
)
2
=
a
2
+ 2
ab
+
b
2
(
a
–
b
)
2
=
a
2
– 2
ab
+
b
2
a
3
+
b
3
= (
a
+
b
)(
a
2
–
ab
+
b
2
)
a
3
–
b
3
= (
a
–
b
)(
a
2
+
ab
+
b
2
)
(
a
+
b
)
3
=
a
3
+ 3
a
2
b
+ 3
ab
2
+
b
3
=
a
3
+
b
3
+ 3
ab
(
a
+
b
)
(
a
–
b
)
3
=
a
3
– 3
a
2
b
+ 3
ab
2
–
b
3
=
a
3
–
b
3
– 3
ab
(
a
–
b
)
