\[x(3x - 19) + (3x - 4)(2x + 9) =\]
\[= 3x² - 19x + 6x^{2} + 27x - 8x - 36 =\]
\[= 9x^{2} - 36 =\]
\[= (3x - 6)(3x + 6) =\]
\[= 3 \cdot 3 \cdot (x - 2)(x + 2) =\]
\[= 9 \cdot (x - 2)(x + 2).\]