《手机手打》{1}:因为{an}为等比,a1+a2=3,a3+a4=12所以a1+a1*q=3,a1*q＾2+a1*q＾3=12,合并得3q＾2=12,得q=±2,【1】q=2得a1=1,则a2*a3=8【2】q=-2得a1=-3,则a2*a3=-72{2}：因为为等比,所以a2*a3*a4*a5*a6*a7*a8*a9=(...