1/2=5n/3
$\displaystyle \frac{1}{2} = \frac{5n}{3}$
I want to "clear the fractions." The least common multiple of 2 and 3 is 6, so:
$\displaystyle 6 \cdot \frac{1}{2} = 6 \cdot \frac{5n}{3}$
$\displaystyle 3 = 2 \cdot 5n$
$\displaystyle 3 = 10n$
$\displaystyle n = \frac{3}{10}$
-Dan