问题 选择题

(x+1)2+(x+1)11=a0+a1(x+2)+a2(x+2)2+…+a10(x+2)10+a11(x+2)11,则a1=(  )

A.-12

B.-10

C.9

D.11

答案

(x+1)2+(x+1)11=[(x+2)-1]2+[(x+2)-1]11

则a1=

C12
(-1)+
C1011
(-1)10=-2+11=9,

故选C.

判断题
选择题