题干

直线过点P(﹣3,1),且与x轴,y轴分别交于A,B两点.
(Ⅰ)若点P恰为线段AB的中点,求直线l的方程;
(Ⅱ)若 AP→ = 2PB→ ,求直线l的方程.
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答案(点此获取答案解析)

解:(Ⅰ)设A(x,0)、B(0,y),由中点坐标公式得:x=﹣6,y=2,

∴直线l的方程为 =1,

即x﹣3y+6=0.

(Ⅱ)设A(x,0)、B(0,y),若 {

同类题2

阅读下面短文,掌握大意,然后从1-20各题所给的四个选项(A、B、C和D)中,选出最佳答案。

        My husband, Bob, died in January 2004. His death was unexpected as well. I 1 condolences(哀悼)from people I hadn't heard from in years: letters, cards, flowers, calls, and visits. I took a bad knock with 2. I was so struggling to3the whys and hows of this terrible thing that had happened to my family, knowing in my heart that there really were no 4. It's just all so sad.

        One message5me deeply. I received a letter from my best friend from sixth6 through high school. We had drifted somewhat since 7 in 1959, as she stayed in our home town and I did not. 8 it was the kind of friendship that could quickly resume even if we9touch for five or ten years.

        Her husband, Peter, had died perhaps 20 years ago at a young age, 10her with deep sorrow and heavy 11: finding a job and raising three young children. She and Pete, 12 Bob and I, had shared one of those rare, close, "love-of-your-life-you-can-never-forget" 13.

        In her letter she 14 an anecdote about my mother who had passed away years ago. She wrote, "When Pete died, your dear mother 15me and said, 'Trudy, I don't know what to say...so I'll just say I love you.'"

        She closed her letter to me repeating my mother's words of so long16, "Bonnie, I don't know what to say...so I'll just say I love you."

        I felt I 17 almost hear my mother speaking to me now. What a 18 message of sympathy! How dear of my friend to cherish it all those years and then 19 it on to me.I love you. 20 words. A gift. A legacy(遗赠物).

同类题3

根据短文内容,选择正确答案。

B

    Sam was a fifteen­year­old boy living with his little sister, Julie. Their parents passed away long ago. Sam had to take care of Julie by himself.

One day, Sam woke up at three in the morning as usual. When Julie was sleeping alone, Sam left their little house to send newspapers. When he found an old man sitting in front of their house, Sam was so surprised that he stopped to look at him closely. It was an icy morning and he looked very cold.

    The poor old man didn't have anything to cover himself with. Sam went into his house to get the old man a blanket(毯子). However, there were no extra blankets, so Sam thought hard and took his father's coat. It was the only thing of his father's that he had left. Sam wrote a short note. "Sir, I found you sleeping in front of my house. This is my father's coat. I hope it fits you well." He put the note in a pocket of the coat and covered the old man with the coat. Then he went to work. When he came back, both the man and the coat were gone. Sam thought that it was the best thing he could do with his father's coat.

    That afternoon, Sam hurried home after school because Julie was at home alone. However, Julie and the old man were standing in front of the house, and Julie shouted to Sam, "Brother! He's our grandfather!"

    The grandfather smiled and said, "Sam, thank you for giving me the coat and letting me know how good my grandson is. This coat was the one that I gave my son a long time ago!"