If A is the area of a circle with radiusr and the circle expands as time passes, find dA/dt in terms of dr/dt. So I have, A= π r2
dA/dt = 2π r (dr/dt)

Olga used 100 ounces of flour to make 225 muffins. how many ounces of flour will be used to make 300 muffins?

You need to solve a system of equations. you decide to use the elimination method. which of these is not allowed? 3x - 2y = 7 3x + 4y = 17 equation 1 equation 2

Ian is in training for a national hot dog eating contest on the 4th of july. on his first day of training, he eats 4 hot dogs. each day, he plans to eat 110% of the number of hot dogs he ate the previous day. write an explicit formula that could be used to find the number of hot dogs ian will eat on any particular day.