Which sum does the model below represent? a. 4 + (-7) = -3 b. 4 + 7 = 11 c. 8 + (-3) = 4 d. 11 + (-4) = -3

David estimated he had about 20 fish in his pond. a year later, there were about 1.5 times as many fish. the year after that, the number of fish increased by a factor of 1.5 again. the number of fish is modeled by f(x)=20(1.5)^x. create a question you could ask that could be answered only by graphing or using a logarithm.