Differentiate how? PART 1

Calculus Level 3

If ${ x }^{ y }={ e }^{ x-y }$ , then $\frac { dy }{ dx } = \text{\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_}.$

\frac { x-y }{ (1+\log { x)^{ 2 } } }

\frac { \log { x } }{ (1+\log { x)^{ 2 } } }

\frac { x-y }{ 1+\log { x } }

\frac { y-x }{ x(1+\log { x) } }