Each unit of a product can be made on either machine a or machine b. the nature of the machines makes their cost functions differ. machine a: upper c left parenthesis x right parenthesis equals 30 plus startfraction x squared over 6 endfraction machine b: upper c left parenthesis y right parenthesis equals 140 plus startfraction y cubed over 9 endfraction total cost is given by c(x, y)equalsupper c left parenthesis x right parenthesisplusupper c left parenthesis y right parenthesis. how many units should be made on each machine in order to minimize total costs if xplusyequals17 comma 030 units are required? the minimum total cost is achieved when nothing units are produced on machine a and nothing units are produced on machine b.