\(\frac{x+3}{x^2-4}.\frac{8-12x+6^2-x^3}{9x+27}\)
\(=\frac{x+3}{x^2-4}.\frac{-x^3+6x^2-4}{9x+27}\)
\(=\frac{\left(x+3\right)\left(-x^3+6x^2-4\right)}{\left(x^2-4\right)\left(9x+27\right)}\)
\(=\frac{\left(x+3\right)\left(-x^3+6x-4\right)}{9\left(x+3\right)\left(x^2-4\right)}\)
\(=\frac{-x^3+6x^2-4}{9\left(x^2-4\right)}\)
Mk ko chắc
(x+3 )/ (x-2)(x+2) . [(2-x)^3 / 9(x+3)]
= -(x-2)^2 / [(x+2).9]