Round 25,000 to the nearest ten thousand

Can someone me and plz do the problem

Which graph represents the linear function below? y-3=1/2(x+2)

Atreasure chest sinks at a rate no less than 20 feet er second. the floor of the icean is at most at -4,200 feet. will the tresure chest reach the ocean floor in less than 3 minutes? explain.