Atextbook store sold a combined total of 423 math and psychology textbooks in a week. the number of math textbooks sold was 45 more than the number of psychology textbooks sold. how many textbooks of each type were sold?

Harold wrote this equation to model the level of water in a pool over time. the variable x represents time in hours. f(x) = 3,500 - 225x which statements about the situation are true? check all that apply. the water level is rising. the water level is falling. the initial level of water in the pool was 3,500 units. the initial level of water in the pool was 225 units. the pool was empty after 14 hours. the water was 2,600 units high after 4 hours.