If $f ( x , y ) = y e ^ { x y }$

Essay

If $f ( x , y ) = y e ^ { x y }$ , find the values $x _ { 0 }$ for which $f \left( x _ { 0 } , 5 \right) = 5$ , and then find an equation of the plane tangent to the graph of $f$ at $\left( x _ { 0 } , 5,5 \right)$ .