Urgent me pls 80 points ! which expression is equivalent? (5x−2y2)−3 a) 125x6 y6 b) x6 125y6 c) x6y6 125 d) x8 125y8

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.