等差数列{an}中S9=-36,S13=-104,等比数列{bn}中b5=a5,b7=a7,则b6=( )
等差数列{an}中S9=-36,S13=-104,等比数列{bn}中b5=a5,b7=a7,则b6=( )
Sn为等差数列{an}的前n项和,S9=-36,S13=-104,等比数列{bn}中,b5=a5,b7=a7,则b6等于
3道数列题1.等差数列an的前n项 和为sn,s9=-18,s13=-52,等比数列bn中,b5=a5,b7=a7,求b
(2010•宿松县三模)等差数列{an}的前n项和为Sn,S9=-18,S13=-52,等比数列{bn}中,b5=a5,
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
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=?
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?
在等比数列中{an}和等差数列{bn}中,a5=b5,2a5-a2*a8=0,则b3+b7=
已知等差数列{an}和正项等比数列{bn},a1=b1=1,a3+a5+a7=9,a7是b3、b7的等比中项...
已知{Bn}为等比数列,B5=2,则B1*B2*B3*B4*B5*B6*B7*B8*B9=2^9.若{An}为等差数列,