Thread: simplify complex fraction

(x-9)/(x/9-9/x)

Originally Posted by ailmasum

(x-9)/(x/9-9/x)

$\displaystyle \displaystyle \frac {x-9 } { \frac {x}{9} -\frac {9}{x}} = \frac {x-9 } { \frac {x^2 -81}{9x} } = \frac {\frac {x-9}{1}}{\frac {x^2 -81}{9x}} = \frac {9x(x-9)}{x^2-81} = \frac {9x^2-81x}{x^2-81} = $