Please please help!

An island is 9 mi from the nearest point on a straight shoreline; that point is 10 mi from a power Let x be the distance from the shoreline closest to the island and the point where the station (see figure). A Utility company plans to lay electrical cable underwater from the island to cable leaves the shore. the shore and then underground along the shore to the power station. Assume that is costs $1600/mi to lay cable underwater and $800/mi to lay underground cable. At what point should the The cost is minimized when x is mi. underwater cable meet the shore to minimize the cost of the project? (Type an exact answer.) Island The minimum installation cost is $. Cable (Round to the nearest cent as needed.) 9 my Power Station 10 mi