The answer would be B.
Unit rate is something per time unit or other unit.
Hope this helps!
Answer:8
Step-by-step explanation:
5x+30- 2x+9
3x+39 is the expression.
Given functions are


The total number of ducks and swans in the lake after n months can be determined by adding the functions s(n) and d(n).





Taking 2 as common, we get

Hence The total number of ducks and swans in the lake after n months is