72y^5 + 18y^2 what is the gcf? or is this prime?

Need on this one asap im almost done with this subject

Aremote-controlled boat can travel at 4 feet per second in calm water. the boat traveled 48 feet with the current, and then it traveled 16 feet against the current in the same amount of time. how fast is the current?

The function f(x) is shown in this graph the function g(x)=6x