0Algebra:
1. (a + b) = a + 2ab + b
2. (a – b) = a – 2ab + b
3. (a + b) (a – b) = a – b
4. (x + a)(x + b) = x + (a + b)x + ab
5. (x + a)(x – b) = x + (a – b)x – ab
6. (x – a)(x + b) = x + (b – a)x – ab
7. (x – a)(x – b) = x – (a + b)x + ab
8. (a + b) = a + b + 3ab(a + b)
9. (a – b) = a – b – 3ab(a – b)
10. (x + y + z) = x + y + z + 2xy +
2yz + 2xz
11. (x + y – z) = x + y + z + 2xy
– 2yz – 2xz
12. (x – y + z) = x + y + z – 2xy –
2yz + 2xz
13. (x – y – z) = x + y + z – 2xy
+ 2yz – 2xz
14. x + y + z – 3xyz = (x + y + z)(x
+ y + z – xy – yz -xz)
15. (x + a) (x + b) (x + c) = x + (a + b
+c)x + (ab + bc + ca)x + abc
16. x + y = (x + y) (x – xy + y )
17. x – y = (x – y) (x + xy + y )
