The amount of a radioactive substance, y, decays exponentially such that its half-life is 8 days. In other words, the amount of any sample decays to exactly half in that time period. Write a differential equation in terms of y and t, in days, to represent the rate of decrease in the amount of the substance. = -0.0866y O O di dy dt dt = -0.1732y = -0.0433y = 0.1732y 90 91 92 93 94 95 96 97 98 99 Finish