# How do you simplify (2x - 9)/(9 - 2x)?

Assuming $x \ne \frac{9}{2}$ (in which case the division is undefined:
$\frac{2 x - 9}{9 - 2 x} = \frac{\left(- 1\right) \left(9 - 2 x\right)}{\left(9 - 2 x\right)} = - 1$