Please solve and circle answers for each part and please make legible. You do not need to show work, just need the answers

A chemical substance has a decay rate of 8.8% per day. The rate of change of an amount N of dN the chemical after t days is given by dt = - 0.088N. a) Let No represent the amount of the substance present at t= 0. Find the exponential function that models the decay. b) Suppose that 400 g of the substance is present at t = 0. How much will remain after 3 days? c) What is the rate of change of the amount of the substance after 3 days? d) After how many days will half of the original 400 g of the substance remain?The annual consumption of beef per person was about 64.6 lb in 2000 and about 61.5 lb in 2007. Assume B(t), the annual beef consumption t years after 2000, is decreasing according to the exponential decay model. a) Find the value of k, and write the equation. b) Estimate the consumption of beef in 2010. c) In what year (theoretically) will the consumption of beef be 10 lb?A company determined that the marginal cost, C'(x) of producing the xth unit of a product is given by C'(x) =x" - 4x. Find the total cost function C, assuming that C(x) is in dollars and that fixed costs are $2000. C(x) =