Using the terms B, D, I and E construct equations to express the following (b = birth d = deaths i = immigration e = emigration

a) a population in equilibrium

b) a declining population

c) an increasing population

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