题目

   Once upon a time a teacher and his student  3 6  down under a big tree near the big grass area．Then suddenly the student asked the teacher，“Teacher，I’m puzzled．How do we  37  our soul mate(知己)?Could you please help me?”    Silent for a few seconds，the teacher then answered，“Well，it’s a pretty hard and easy question．” The teacher 38  ，“Look that way．There is a lot of grass．Why don’t you walk there? But please don’t walk  39  ．On your way，try to find a blade(叶片)of beautiful grass and  40  it and then give it to me．Bu求下列方程的整数（1）11x+5y=7；（2）4x+y=3xy．