A certain forest covers an area of 4200km2. Suppose that each year this area decreases by 5.5%. What will the area be after 12 years?

Question

campbell_st · Answer

are you working on sequences and series...?

anonymous · Answer

idk @campbell_st

campbell_st · Answer

ok... makes it hard to explain, if you don't know. 

do you know how to use the compound interest formula..?

anonymous · Answer

yes but i need it to decrease and idk how to do that one @campbell_st

mertsj · Answer

campbell_st · Answer

ok... so the compound interest formula can be converted to a depreciation formula by changing the sign inside the brackets from + to -

campbell_st · Answer

the formula I know is

$$A = P(1 + \frac{r}{100})^n$$

you can use 

$$A = P(1 - \frac{r}{100})^n$$

campbell_st · Answer

r = 5.5   P = 4200 and n = 12

hope it helps

anonymous · Answer

thank you i will try it @campbell_st

anonymous · Answer

i cant get it right @campbell_st

campbell_st · Answer

why, what do you get as an answer..?