Multiply : \( (4x^2 + y^2 + 9z^2 + 2xy + 3yz – 6xz) \) by \( (2x – y + 3z) \)

\[ (4x^2 + y^2 + 9z^2 + 2xy + 3yz – 6xz)(2x – y + 3z) \] \[ = 8x^3 – 4x^2y + 12x^2z + 2xy^2 – y^3 + 3y^2z + 18xz^2 – 9yz^2 + 27z^3 \] \[ \quad + 4x^2y – 2xy^2 + 6xyz + 6xyz – 3y^2z + 9yz^2 – 12x^2z + 6xyz – 18xz^2 \] \[ = 8x^3 – y^3 + 27z^3 + 18xyz \]