Find the vertex of f(r)=-(r-12)(r+3)

Ellen makes and sells bookmarks. she graphs the number of bookmarks sold compared to the total money earned. why is the rate of change for the function graphed to the left?

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.

Atown has a population of 17000 and grows at 2.5% every year. to the nearest year, how long will it be until the population will reach 19600?