Find the exact value of xy\displaystyle {\left|{{x}{y}}\right|} given:

{x2+y2=8x2y2=2\displaystyle {\left\lbrace\begin{array}{c} {x}^{{2}}+{y}^{{2}}={8}\\{x}^{{2}}-{y}^{{2}}={2}\end{array}\right.} 

 xy=\displaystyle {\left|{{x}{y}}\right|}=