[tex]\dfrac{3ax-n}{5}=-4\qquad\text{multiply both sides by 5}\\\\3ax-n=-20\qquad\text{add n to both sides}\\\\3ax=n-20\qquad\text{divide both sides by 3a}\neq0\\\\\boxed{x=\dfrac{n-20}{3a}}[/tex]
