What is the value of ‘x’?

What value of x is in the solution set of 4x – 12 s 16 + 8x?

Witch represents the inverse of the function f(x)=1/4x-12

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.