# Suppose the acreage of forest is decreasing by 2% per year because of development. If there are currently 4,500,000 acres of forest, determine the amount of forest land after each of the following number of years?

Feb 8, 2018

See below an explanation of how to do it, as cannot directly answer question as no number of years was given...

But use:

$A = 4 , 500 , 000 \times {\left(0.98\right)}^{N}$ Where $N$ is the years.

#### Explanation:

Even though there's no years, I will do a demonstration of how to do it for certain years

Even though this isn't money related, I would use compound interest, where a certain percentage of a value is lost over a certain amount of time. It is repeated loss of money or other over a period of time.

$A = P \times {\left(1 + \frac{R}{100}\right)}^{N}$

Where $A$ is the amount after the amount of time, $P$ is the original amount, $R$ is the rate and $N$ is the number of years.

Plugging our values into the formula we get:

$A = 4 , 500 , 000 \times {\left(1 - \frac{2}{100}\right)}^{N}$

As you did not state the number of years we will leave this blank for the moment. Notice that we minus as it is decreasing...

$\frac{2}{100} = 0.02$

Therefore instead of $\frac{2}{100}$ minus this from $1$ and re-do the formula:

$A = 4 , 500 , 000 \times {\left(0.98\right)}^{N}$

Let's just do an example:

Someone puts £50,000 in a bank, he gets interest of 2.5% each year, calculate the amount he would have after $3$ years:

(Focus on that it is addition as he is getting money)

Using the formula $A = P \times {\left(1 + \frac{R}{100}\right)}^{N}$ we get...

A=£50,000xx(1+2.5/100)^3

$\frac{2.5}{100} = 0.025$

Therefore we add this onto $1$ giving us $1.025$ This gets us...

A=£50,000 xx (1.025)^3

Plug this in your calculator you get...

=£53844.53125 which is rounded to £53844.53

Just do the exact same for your question, putting with the values I gave, just input the power as the amount of years that you want to work out.