Answer:
The number of animals of the species will be left in 2025 = 2519 animals
Explanation:
The number of animals of a certain species in 1980 = 20000
The rate of decrease each year = 4.5 %
The number of animals left in 2025 = ???
The number of years between 1980 and 2025 = 45
By formula of depreciation,

where Pn is the population in 2025
P is the population in 1980
R is the rate of decrease in population
Substituting the values in the equation, we get

=

=2518.7 = 2519 species.