Pls help me i havre ths due today

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

Marcus and cody both leave the park at the same time, but in opposite directions. if cody travels 6 mph faster than marcus and after 4 hours they are 64 miles apart, how fast is each traveling? solve using rare times time = distance.

What are the solutions of the following system? y=-2x^2 y=x-2