So basically you just want to isolate the variable. So you want n on a side all by itself. so first you multiply by -2 to both sides, that will leave you with the equation n+4=18, then you subtract 4 from both sides, this will give you the equation n=14. To make sure this solution is correct, you can plug it back into the equation filling 14 in for n, this equation is 14+4/-2=-9, and this solution works. Hope this helped :)
