Expand $(3x - 2)(3x - 6)$.

(D) To expand the expression $(3x - 2)(3x - 6)$,we use the distributive property or the algebraic identity $(x + a)(x + b) = x^2 + (a + b)x + ab$.
Given expression: $(3x - 2)(3x - 6)$
Let $u = 3x$. Then the expression becomes $(u - 2)(u - 6)$.
Expanding this: $u^2 + (-2 - 6)u + (-2)(-6)$
$= u^2 - 8u + 12$
Now,substitute $u = 3x$ back into the expression:
$= (3x)^2 - 8(3x) + 12$
$= 9x^2 - 24x + 12$