The numbers of girls in a second grade class in 4 less than the number of boys. let b represent the number of boys in the class, and write an expression that represents the number of girls ( write an expression! )

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.