Question

X cube + 27 y cube + 8zcube- 18 x y z

Answer 1

Answer:

x^3+27y^3+8z^3-18xyz

= x^3+(3y)^3+(2z)^3-3(x)(3y)(2z)

= (x+3y+2z)[(x)^2+(3y)^2+(2z)^2-(x)(3y)-(3y)(2z)-(2z)(x)]

= (x+3y+2z)(x^2+9y^2+4z^2-3xy-6yz-2zx)

By using the identity,

a^3+b^3+c^3-3abc = (a+b+c)(a^2+b^2+c^2-ab-bc-ca)