## Algebra: A Combined Approach (4th Edition)

$n=30$
$\dfrac{n}{10}=9-\dfrac{n}{5}$ Multiply the whole equation by $10$: $10\Big(\dfrac{n}{10}=9-\dfrac{n}{5}\Big)$ $n=90-2n$ Solve for $n$: $n+2n=90$ $3n=90$ $n=\dfrac{90}{3}$ $n=30$