Answer:
n<-9
Explanation:
18+n/-3>21
Minus 18 on both sides to eliminate 18 on the left side.
n/-3>21-18
n/-3>3
Multiply -3 on both sides so the variable is on it's own.
n>3*-3
Then u see that there is multiplying on both sides with a negative so u switch signs.
n<-9