题目

People are being lured (引诱) onto Facebook with the promise of a fun, free service without realizing they’re paying for it by giving up large amounts of personal information. Facebook then attempts to make money by selling their data to advertisers that want to send targeted messages.Most Facebook users don’t realize this is happening. Even if they know what the company is up to, they still have no idea what they’re paying for Facebook because people don’t really know what their personal data is worth.The biggest problem, however, is that the company keeps changing the rules16．若将函数f（x）=x6表示为f（x）=a0+a1（1+x）+a2（1+x）2+…+a6（1+x）6，其中a1，a2，…，a6为实数，则a3等于-20．