题目

已知实数，满足约束条件，则的最大值____． 答案：2 【解析】根据不等式组画出可行域，是一个封闭的三角形区域，目标函数，可化为，当目标函数过点时函数有最大值，代入得到2．故答案为：2．阅读短文，判断下列句子的正误。I'm Amy. My uncle has a farm. It is big. There are ten cats, six hens and seven cows on the farm. There are some vegetables, too. They are tomatoes, potatoes, onions and carrots. My uncle likes tomatoes very much. So he grows (种植) many tomatoes on the farm. I like tomatoes, too. We have tomatoes for lunch today. They are yummy!【1】Amy's uncle has a big farm. （______）【2】There are ten dogs, six ducks and seven cows on the farm. （______）【3】Amy's uncle grows four kinds (种类) of vegetables on the farm. （______）【4】Amy's uncle likes carrots very much. （______）【5】They have potatoes for lunch. They are yummy. （______）