Find the following product :
$(2 x-y+3 z)(4 x^{2}+y^{2}+9 z^{2}+2 x y+3 y z-6 x z)$

(D) We use the algebraic identity: $(a+b+c)(a^{2}+b^{2}+c^{2}-ab-bc-ca) = a^{3}+b^{3}+c^{3}-3abc$.
Given expression: $(2x - y + 3z)((2x)^{2} + (-y)^{2} + (3z)^{2} - (2x)(-y) - (-y)(3z) - (3z)(2x))$.
Here,$a = 2x$,$b = -y$,and $c = 3z$.
Applying the identity:
$= (2x)^{3} + (-y)^{3} + (3z)^{3} - 3(2x)(-y)(3z)$
$= 8x^{3} - y^{3} + 27z^{3} - 3(2x)(-y)(3z)$
$= 8x^{3} - y^{3} + 27z^{3} + 18xyz$.