NumberGyan.com
Algebra: Factorisation
a
2
+ 2ab + b
2
a
2
+ 2ab + b
2
= (a + b)
2
a
2
− 2ab + b
2
a
2
− 2ab + b
2
= (a − b)
2
a
2
− b
2
a
2
− b
2
= (a + b)(a − b)
x
2
+ (a+b)x + ab
x
2
+ (a+b)x + ab = (x + a)(x + b)
a
3
+ 3a
2
b + 3ab
2
+ b
3
a
3
+ 3a
2
b + 3ab
2
+ b
3
= (a + b)
3
a
3
− 3a
2
b + 3ab
2
- b
3
a
3
− 3a
2
b + 3ab
2
- b
3
= (a − b)
3
a
2
+ b
2
+ c
2
+ 2(ab + bc + ca)
a
2
+ b
2
+ c
2
+ 2(ab + bc + ca) = (a + b + c)
2
