已知等比数列{an}中,a3a11=4a7,数列{bn}是等差数列,且b7=a7则b5+b9=
已知等比数列an中,a3a11=4a7,数列bn是等差数列,且b7=a7,则b5+b9的值为多少
已知等比数列 ﹛an﹜ 中,有a3a11=4a7,数列﹛bn﹜是等差数列,且b7=a7,则b5+b9等于?
等比数列an中,有a3*a11=4a7,数列bn是等差数列,且b7=a7,则b5+b9=
等比数列{an}中,有a3·a11=4a7,数列{bn}是等差数列,且b7+a7,则b5+b9=?
公差不为零的等差数列{an}中,有2a3-a7²+2a11=0,数列{bn}是等比数列,且b7=a7,则b6b
每项都不为0的等差数列{an}中,2a3-a7^2+2a11=0,数列{bn}是等比数列,且b7=a7,则b6*b8等于
在公差不为0的等差数列an中,有2a3-a7²+2a11=0,数列bn是等比数列,且b7=a7
正项的等差数列{an}中,2a3-a72+2a11=0,数列{bn}是等比数列,且b7=a7,则b6b8=______.
等差数列{an}中,a3+a11=8,数列{bn}是等比数列,且b7=a7,则b6b8的值为 ( )
(1)已知{an}是各项均不为0的等差数列,数列{bn}是等比数列,若a1-a7的平方+a13=0,且b7=a7,则b3
等差数列{a}中,an不等于0,2a3+a7^2+2a11=0,数列{b}是等比数列,且b7=a7,则b6b8=?
公差不为零的等差数列{an}中,有2a3-a7的平方+2a11=0,数列{bn}是等比数列,且b7=a7,则b6b8=?