The Total solution for NCERT class 6-12
27x3-y3-z3-9xyz= (3x)3 + (-y)3 + (-z)3 – 3 x3x x (-y) (-z)= (3x – y – z) [(3x)2 + (-y)2 + (-z)2 –3x x (-y) – (-y) (-z)- (- z x 3x)]= (3x-y – z) (9x2 + y2 + z2 +3xy – yz + 3zx)