Solve the problem. Bob owns a watch repair shop.  He has fou…

Solve the problem. Bob owns a watch repair shop.  He has found that the cost of operating his shop is given by cx=2×2-184x+67{“version”:”1.1″,”math”:”cx=2×2-184x+67″}, where c is cost and x is the number of watches repaired.  How many watches must he repair to have the lowest cost?