题目

已知2x+1的平方根是±5，则x= 答案：12 ． 【考点】平方根． 【分析】依据平方根的定义可知2x+1=25，从而可求得x的值． 【解答】解：∵2x+1的平方根是±5， ∴2x+1=25． 解得：x=12． 故答案为：12． 【点评】本题主要考查的是平方根的定义，依据平方根的定义列出关于x的方程是解题的关键．3、My favorite hobby is reading. I like reading novels, 76．            newspapers, magazine and so on. When I was 9 years 77．            old ,I caught bad cold . I had to stay at home for several 78．            weeks. My mother bought to me some novels. Soon I 79．            was attracted by the stories. Since then I made use of my 80．            spare time to read. And reading does give me many help. 81．            Recently, I have surfed the internet at home ,on that I’ve 82．            found that many students like read as I do. We exchange 83．            our reading experience on line but we become good 84．            friends .Reading brings me all happiness and friendship. 85．