Pls help me solve this one

Dear Student,

27 x^{3} + y^{3} + z^{3} - 9 xyz = {(3 x)}^{3} + y^{3} + z^{3} - 3 \times (3 x) (y) (z) Using identity, a^{3} + b^{3} + c^{3} - 3 abc = (a + b + c) (a^{2} + b^{2} + c^{2} - ab - bc - ca) {(3 x)}^{3} + y^{3} + z^{3} - 3 \times (3 x) (y) (z) = (3 x + y + z) [{(3 x)}^{2} + y^{2} + z^{2} - 3 xy - yz - 3 xz] = (3 x + y + z) [9 x^{2} + y^{2} + z^{2} - 3 xy - yz - 3 xz]

Regards