\(-2x\left(-3x+3\right)-6\left(x+3\right)^2\\ =\left(6x^2-6x\right)-6\left(x^2+6x+9\right)\\ =6x^2-6x-\left(6x^2+36x+54\right)\\ =6x^2-6x-6x^2-36x-54\\ =-42x-54\)
-2x(-3x + 2) - 6(x + 3)²
= 6x² - 4x - 6(x² + 6x + 9)
= 6x² - 4x - 6x² - 36x - 54
= -40x - 54