# How do you solve 9/4=(r-10)/r?

Mar 7, 2018

$r = - 8$

#### Explanation:

$\frac{9}{4} = \frac{r - 10}{r}$

$\left(9\right) \left(r\right) = 4 \left(r - 10\right)$

$9 r = 4 r - 40$

Add $- 4 r$ on both sides

$9 r - 4 r = 4 r - 40 - 4 r$

$5 r = - 40$

Divide both sides by $5$

$\frac{\cancel{5} r}{\cancel{5}} = \frac{- 40}{5}$

$r = - 8$