Remember, if you add negative four, you're really subtracting four, or if you take away negative four, you're really adding four.
-n+(-4)-(-4n)+6
-n-4+4n+6 simplify
{-n+4n are like terms, so combine them. -n+4n is exactly the same as 4n-n, so flip them around if it helps. Just remember to keep the sign with the right number. Same thing with -4+6.}
Answer:
3n+2