-1/8,1/2,-2,8;或者8,-2,1/2,-1/8.
a1*a2*a3*a4=1,因为等比,所以a2*a3=a1*a4,即（a2*a3）^2=1,所以a2*a3=-1,或者a2*a3=1.又a2+a3=-3/2,两个等式联立,若a2*a3=1,则方程组无解；若a2*a3=-1,则a2=2,a3=-1/2；或a2=-1/2,a3=2.可得,q=-4,a1=-1/8;或者q=-1/4,a1=8.