等比数列{an},所以设 比例为 q,那么a1=a1×1a2=a1×qa3=a1×q^2a4=a1×q^3...a10=a1×q^9a1*a8=a1*a1*q^7a1*a2*a3*a4*a5*a6*a7*a8*a9*a10=a1^10 * q^(1+2+...+9)=a1^10 * q^45出题的人大概打错了吧,a1*a10=81吧.如果...