题目

Hello, everyone(每个人)! My name is Bob. I live in Toronto, Canada. It's a very beautiful city. My parents are from France. They speak French. And I can speak English and French.      I am 13 years old and my birthday is in November. I'm a middle school student. There are thirteen girls and fifteen boys in my class. They are from five countries. They all come to learn English. There are eight Chinese students in my class and six of them are my good friends. I like China very much because it is a great country. I want to learn Chinese. And I want to go to China. 根据短文内某工厂生产一种产品，当生产数量至少为10吨，但不超过50吨时，每吨的成本y（万元/吨）与生产数量x（吨）的函数关系的图象如图所示．（1）求y关于x的函数解析式，并写出x的取值范围；（2）当生产这种产品每吨的成本为7万元时，求该产品的生产数量． （1）y=﹣x+11（10≤x≤50）；（2）每吨成本为7万元时，该产品的生产数量40吨． 【解析】试题分析：（1）设y=kx+b（k≠0），然后利用待定系数法求一次函数解析式解答； （2）把y=7代入函数关系式计算即可得解． 试题解析：（1）设y=kx+b（k≠0）， 由图可知，函数图象经过点（10，10），（50，6），则 ， 解得． 故y=﹣x+11...