The answer is 24 because you have to do 6x4=24
19 feet
convert 2
into an improper fraction
2
= 
hence the length of the wall is 19 feet
I'm assuming you mean to list the terms of the expression. Those are mn, -2n, and +8. There are 3 terms there.
Answer: 3
Step-by-step explanation: 2+2-1=3