A = \( \left( \frac{1}{3} + \frac{3}{x^2 - 3bc} \right) \left( \frac{1}{27 - 32^2} + \frac{1}{x+3} \right) \) với \( x \in ( -1; +\infty ) \)

A = \( \left( \frac{1}{3} + \frac{3}{x^2 - 3bc} \right) \left( \frac{1}{27 - 32^2} + \frac{1}{x+3} \right) \)
với \( x \in ( -1; +\infty ) \)