在2014年巴西世界杯足球赛前夕，某体育用品店购进一批单价为40元的球服，如果按单价60元销售，那么一个月内可售出240套．根据销售经验，提高销售单价会导致销售量的减少，即销售单价每提高5元，销售量相应减少20套．设销售单价为x（x≥60）元，销售量为y套．

（1）求出y与x的函数关系式．

（2）当销售单价为多少元时，月销售额为14000元；

（3）当销售单价为多少元时，才能在一个月内获得最大利润？最大利润是多少？

参考公式：抛物线y=ax²+bx+c（a≠0）的顶点坐标是($-\frac{b}{2a}$,$\frac{4ac-b^2}{4a}$)．

   Maria lives in the beautiful countryside．She usually gets up early in the morning，1she's never late for schoo1．After getting up，she often showers and has a good breakfast．Then she2 for school at around 6：303her home is very far from schoolshe likes riding her bike better than4the bus．It takes her about an hour5her bike．It's so long! On the way，she sings and sings so she always feels6．Also she thinks that it's good for her health7to school by bike．
   After school she usually goes back8with her friend，Linda．Linda’s home is nearer than Maria's． It's only three miles from her home9schoo1．Linda likes riding，too．And she also thinks that it is a good10of transportation．