Let $A, B, C, D \in \mathbb{R^*_+}$.
Is it possible to solve $$ \max_{ \substack{0 \leq x\leq A \\ 0\leq y\leq B}} \frac{1+x+y}{(1+Cx)(1+Dy)} $$
Let $A, B, C, D \in \mathbb{R^*_+}$.
Is it possible to solve $$ \max_{ \substack{0 \leq x\leq A \\ 0\leq y\leq B}} \frac{1+x+y}{(1+Cx)(1+Dy)} $$