Formulate but do not solve the following exercise as a linear programming problem.

Perth Mining Company operates two mines for the purpose of extracting gold and silver. The Saddle Mine costs $$14,\frac{000}{?}$ day to operate, and it yields $45$ oz of gold and $3500$ oz of silver each of $x$ days. The

Horseshoe Mine costs $$15,\frac{500}{?}$ day to operate, and it yields $75$ oz of gold and $900$ oz of silver each of $y$ days. Company management has set a target of at least $420oz$ of gold and $8,000oz$ of silver. How many

days should each mine be operated so that the target can be met at a minimum cost, $C?$

$C=$

subject to the constraints

gold

silver

$x0$

$y0$