Question

A certain forest covers an area of

3400 km2. Suppose that each year this area decreases by 7%. What will the area be after 15 years?

Answer 1

The general equation for the area of the forest after t years is
A(t)=4300*(.93)^t
.93 since 7 percent decrease means 93 percent stays behind. Now plug in t=12
A(12)=4300(.93)^12=1799.964
So about 1800Km^2 will be left after 12 years.

Answer 2

3400(0.93)^t

3400(0.93)^15= 1144.782931 km2