Help me asap PLEASE. this makes no sense

Which of these choices show a pair of equivalent expressions?

Create a question with this scenario you could ask that could be answered only by graphing or using logarithm. 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.

How to write four times a number,minus 6,is equal to theee times the number+8 as an equqtion