(x^(2)-3x-54)/(x^(2)-18x+81)*(x^(2)+12x+36)/(x+16)
[tex] \frac{x^2-3x-54}{x^2-18x+81} * \frac{x^2+12x+36}{x+16} =\\ \\ = \frac{(x-9)(x+6)}{(x-9)^2} * \frac{(x+6)^2}{x+16} = \\ \\ = \frac{x+6}{x-9} * \frac{(x+6)^2}{x+16} = \\ \\ = \frac{(x+6)^3}{(x-9)(x+16)}[/tex]
