Answer
$y'=\dfrac{e^{x}}{(1-e^{x})^{2}}$
Work Step by Step
$y=\dfrac{e^{x}}{1-e^{x}}$
Differentiate using the quotient rule
$y'=\dfrac{(1-e^{x})(e^{x})'-(e^{x})(1-e^{x})'}{(1-e^{x})^{2}}=\dfrac{(1-e^{x})(e^{x})-(e^{x})(-e^{x})}{(1-e^{x})^{2}}=...$
Evaluate the products in the numerator
$...=\dfrac{e^{x}-e^{2x}+e^{2x}}{(1-e^{x})^{2}}=\dfrac{e^{x}}{(1-e^{x})^{2}}$
$y'=\dfrac{e^{x}}{(1-e^{x})^{2}}$