[tex]5x+6=9n-42\qquad\text{subtract 6 from both sides}\\\\5x=9n-48\qquad\text{divide both sides by 5}\\\\\boxed{x=\dfrac{9n-48}{5}}\\----------------------------\\9n-42=5x+6\qquad\text{add 42 to both sides}\\\\9n=5x+48\qquad\text{divide both sides by 9}\\\\\boxed{n=\dfrac{5x+48}{9}}[/tex]