Amy is backpacking with her friends. At the base of a hill, they find the temperature to be 24.1°C. As they reach the summit situated at a height of one kilometer, they notice that the temperature has dipped to 18°C. If h represents the height and T represents the temperature, which of the following equations can be used to model this situation?

Quick! a survey of 57 customers was taken at a bookstore regarding the types of books purchased. the survey found that 33 customers purchased mysteries, 25 purchased science fiction, 18 purchased romance novels, 12 purchased mysteries and science fiction, 9 purchased mysteries and romance novels, 6 purchased science fiction and romance novels, and 2 purchased all three types of books. a) how many of the customers surveyed purchased only mysteries? b) how many purchased mysteries and science fiction, but not romance novels? c) how many purchased mysteries or science fiction? d) how many purchased mysteries or science fiction, but not romance novels? e) how many purchased exactly two types of books?