Simplify each of the following expressions :

(i) (x+y+z)2+


(ii) (x+y-2z)2-x2y2 - 3z2+4xy


(iii) (x2x + 1)2 - (x2 + x + 1)2

(i) Using identity,


(ii) Using the identity,




(iii) Using the identity,




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