Answer
$n=9$
Work Step by Step
$\frac{2}{3}n=6$
$\frac{2}{3}n\times\frac{3}{2}=6\times\frac{3}{2}\longrightarrow$ multiply both sides by $\frac{3}{2}$
$n=\frac{18}{2}=9$
To check, substitute the value for n and see of the result is true.
$(\frac{2}{3})(9)=6$
$\frac{18}{3}=6$
$6=6\checkmark$