Can someone please help

The depth of a lake at a certain point, wich is a function of the distance of that point from shore, is 30 feet.

Which represents the inverse of the function f(x) = 4x? h(x) = x + 4 h(x) = x – 4 h(x) = x h(x) = x

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?