Amanufacturer of projection tvs must ship a total of at least 1000 tvs to its two central warehouses, x to the first warehouse and y to the second warehouse. each warehouse can hold a maximum of 750 tvs. the first warehouse already has 150 tvs on hand, whereas the second has 50 tvs on hand. it costs $6 to ship a tv to the first warehouse, and it costs $15 to ship a tv to the second warehouse. how many tvs should be shipped to each warehouse to minimize cost?