9514 1404 393
Answer:
A(x) = 20000(0.88)^x
Step-by-step explanation:
The general form of these exponential equations is ...
A(x) = a·b^x
where 'a' is the initial value, and b is the annual growth factor. x is the elapsed time in years.
The growth factor is ...
growth factor = 1 + growth rate
Here, the growth rate per year is -12%, so the growth factor is ...
b = 1 -12% = 88% = 0.88
Of course, the initial value is a=20,000, so the equation is ...
A(x) = 20000(0.88)^x