The oil field has 70 wells. Average production per well is 480 barrels per day. It is forecasted that foreach extra well drilled in field, production per well would be decreased by 5 barrels per day; where as, every well capped(shut down) would increase producton of every remaining well by eight barrels per day. Model oilfield's daily production function f(x), where x is number of wells drilled (x>0) or capped (x<0).