Question

Which equation represents a population of 210 animals that decreases at an annual rate of 14%

Answer 1

So for this, we will be using exponential form, which is y = ab^x (a = initial value, b = growth/decay).

Since we start off with 210 animals, that is our a variable.

Next, since this is *decreasing* by 14%, you are to subtract 0.14 (14% in decimal form) from 1 to get 0.86. That will be your b variable.

Putting everything together, your equation is y = 210(0.86)^x

Answer 2

The equation i.e. used to denote the population after x years is:

P(x) = 490(1 + 0.200 to the power of x

Explanation:

This problem could be modeled with the help of a exponential function.

The exponential function is given by:

P(x) = ab to the power of x

where a is the initial value.

and b=1+r where r is the rate of increase or decrease.

Here the initial population of the animals are given by: 490

i.e. a=490

Also, the rate of increase is: 20%

i.e. r=20%

i.e. r=0.20

Hence, the population function i.e. the population of the animals after x years is:

P(x) = 490(1 + 0.200 to the power of x