[tex]\frac{x^{2} - 3x - 54}{x^{2} - 18x + 81} \times \frac{x^{2} + 12x + 36}{x + 6}[/tex]
[tex]\frac{(x - 9)(x + 6)}{(x - 9)(x - 9)} \times \frac{(x + 6)(x + 6)}{x + 6}[/tex]
[tex]\frac{x + 6}{x - 9} \times \frac{x + 6}{1}[/tex]
[tex]\frac{(x + 6)(x - 6)}{x - 9}[/tex]
[tex]\frac{x^{2} - 12x + 36}{x - 9}[/tex]