The number of bacteria (b) in a batch of refrigerated food is given by the function b(t) = 20t2 − 70t + 300, where t is the temperature of the food in degrees fahrenheit. the function t(h) = 2h + 3 gives the temperature of the food h hours after it is removed from refrigeration. which expression correctly represents the number of bacteria (b) in the food as a function of the number of hours (h) the food is unrefrigerated?