Answer:
a) b + i = d + e
b) b + i < d + e
c) b + i > d + e
Explanation:
Data provided in the question:
b = birth
d = deaths
i = immigration
e = emigration
Now,
a) a population in equilibrium
this means increase in population is equal to decrease in population
i.e
b + i = d + e
b) b) a declining population
this means increase in population is less than decrease in population
i.e
b + i < d + e
c) an increasing population
this means increase in population is increase in decrease in population
i.e
b + i > d + e