So cancel each equation terms on both sides of the equation and move constant to the right side and change its sign. So your answer is A=-3
Your welcome
1. can't be determined cause no info given on the rate of which the population is growing.
2. can't be determined/not true because the initial population of a could be less than b.
3. can't be determined/not true because we don't have enough info to tell how fast they grow and decline.
Let r be a radius of a given circle and α be an angle, that corresponds to a sector.
The circle area is

and denote the sector area as

.
Then

(the ratio between area is the same as the ratio between coresponding angles).

.