Let's solve for n.<span>d=<span><span>3m</span>+<span>7n</span></span></span> Step 1: Flip the equation.<span><span><span> 3m</span>+<span>7n</span></span>=d</span> Step 2: Add -3m to both sides.<span><span><span><span> 3m</span>+<span>7n</span></span>+<span>−<span>3m</span></span></span>=<span>d+<span>−<span>3m</span></span></span></span><span><span> 7n</span>=<span>d−<span>3m</span></span></span> Step 3: Divide both sides by 7.