An investment earns 9% simple interest. What amount of principal is needed to have $4000 after 3 years? Round your answer to the nearest cent.

logv3(x+2)=1

rewrite in exponential form:

logb(x) = y is equal to b^y =x

b = 3, y = 1

now solve for x:

3^1 = x+2)

x = 3-2

x = 1

see the picture for the graph.