question_answer

If \[{{x}^{2}}+{{y}^{2}}-xy=3\]and\[\mathbf{y}-\mathbf{x}=1\], then find \[\frac{xy}{{{x}^{2}}+{{y}^{2}}}\]

A) \[\frac{5}{2}\]              

B) \[\frac{2}{5}\]

C) \[\frac{3}{2}\]              

D) \[\frac{5}{3}\]

E) None of these