[tex]\dfrac{1}{8}ns=q\qquad|\text{multiply both sides by 8}\\\\\not8^1\cdot\dfrac{1}{\not8_1}ns=8q\\\\ns=8q\qquad|\text{divide both sides by}\ s\neq0\\\\\dfrac{ns}{s}=\dfrac{8q}{s}\\\\\boxed{n=\dfrac{8q}{s}}[/tex]