First, you will need to distribute the 6 to (-3n-6). To do this, multiply each term in the parenthesis by 6. You will get-18n-36-5=85. Next, look for like terms, in this case, they would be -36, -5, and 85. Add 36 and 5 to the 85 to get 126. Your new equation will be -18n=126. Then just divide both sides by -18 to get -7.