For each nonzero integer n find all functions f: \mathbb{R} \minus{} \{\minus{}3,0 \} \rightarrow \mathbb{R} satisfying:
f(x\plus{}3)\plus{}f \left( \minus{}\frac{9}{x} \right)\equal{}\frac{(1\minus{}n)(x^2\plus{}3x\minus{}9)}{9n(x\plus{}3)}\plus{}\frac{2}{n} for all x \not\equal{} 0,\minus{}3.
Furthermore, for each fixed n find all integers x for which f(x) is an integer. functionalgebra unsolvedalgebra