为了预防常见传染病的发生，保障学校师生的健康，学校准备印刷宣传手册．现有两家公司可以印刷手册，甲公司提出，每册收材料费5元，另收设计费1500元，乙公司提出，每册收材料费8元，不收设计费．
（1）什么情况下，选甲公司比较合算．
（2）什么情况下，选乙公司比较合算．
（3）什么情况下，两公司一样多．
∵y1=5x+1500，y2=8x，
设人数是x时，
5x+1500=8x，
x=500．
（1）当大于500人，选择甲公司合算，
（2）当小于500人时，选择乙公司合算，
（3）当有500人时，甲乙公司费用一样．
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| When I entered Berkeley, I hoped to earn scholarship. Having been a Straight-A student, I believed I could 1 tough subjects and really learn something. One such course was World Literature given by Professor Jayne. I was extremely interested in the ideas he 2 in class. When I took the first exam, I was 3 to find a 77, C-plus, on my test paper, 4 English was my best subject. I went to Professor Jayne, who listened to my arguments but remained 5 . I decided to try harder, although I didn't know what that 6 because school had always been easy for me. I read the books more carefully, but got another 77. Again, I 7 with Professor Jayne. Again, he listened patiently but wouldn't change his 8 . One more test before the final exam. One more 9 to improve my grade. So I redoubled my efforts and, for the first time 10 the meaning of the word "thorough". But my 11 did no good and everything 12 as before. The last hurdle (障碍) was the final. No matter what 13 I got, it wouldn't cancel three C-pluses. I might as well kiss the 14 goodbye. I stopped working hard. I felt I knew the course material as well as I ever would. The night before the final, I even 15 myself to a movie. The next day I decided for once I'd have 16 with a test. A week later, I was surprised to find I got an A. I hurried into Professor Jayne's office. He 17 to be expecting me. "If I gave you the A's you 18 , you wouldn't continue to work as hard." I stared at him, 19 that his analysis and strategy (策略) were correct. I had worked my head 20 , as I had never done before. I was speechless when my course grade arrived: A-plus. It was the only A-plus given. The next year I received my scholarship. I've always remembered Professor Jayne's lesson: you alone must set your own standard of excellence. | ||||
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