(x+2)10(x2-1)的展开式中x10的系数为(用数字作答)（）。
参考答案：179
解析：
因为(x+2)10(c2-1)=x2(x+2)10-(x+2)10，所以(x+2)10(x2-1)的展开式中x10的系数是(x+2)10展开式的x8的系数减去x10的系数。因为(x+2)10展开式的通项为Tr+1=
，所以令r=0，2分别得x10，x8的系数为1，180，故展开式中x10的系数为180-1=179。
Complete the following passage by using the words in the box. Each word can be used only once. Note that there is one word more than you need.
 rce ___4___ their knowledge, not their muscles. Knowledge workers get paid for their education and their ability to learn. Knowledge workers ___5___ in mind work. They deal with symbols: words, figures, and data.What does all this mean for you? As a future knowledge worker, you can expect to be communicating information. Currently, many jobs ___6___ some form of mind work, and that number will increase sharply in the future. In the new world of work, you can look forward to being in __7___ training to get new skills that will help you keep up with improved technologies. You can also expect to be taking greater control of your career. Gone are the nine-to-five jobs, lifetime security, easy promotions, and even the ___8___ workplace, which you are __9___ with now. Don’t expect the companies will provide you with a clear career path. And don’t wait for someone to “encourage” you. You have to encourage yourself. |