Cevap :

1.    x2 + y2 = (x + y)2 – 2xy

2.    x2 + y2 = (x – y)2 + 2xy

3) (x – y)2 = (x + y)2 – 4xy

4) (x + y)2 = (x – y)2 + 4xy

5) x3 – y3 = (x – y)3 + 3xy (x – y)

6) x3 + y3 = (x + y)3 – 3xy (x + y) 

7) x2 + y2 + z2 = (x + y + z)2 – 2 (xy + xz + yz)   

(a + b)3 = a3 + 3a2b + 3ab2 + b3

(a – b)3 = a3 – 3a2b + 3ab2 – b3

(a + b) (a – b) = a2 – b2