问题
填空题
等比数列an满足a1+a2=3,a2+a3=6,则a7=______.
答案
由a1+a2=a1(1+q)=3①,a2+a3=a1q(1+q)=6②,
②÷①得:q=2,把q=2代入①得到a1=1,
则a7=26=64.
故答案为:64
等比数列an满足a1+a2=3,a2+a3=6,则a7=______.
由a1+a2=a1(1+q)=3①,a2+a3=a1q(1+q)=6②,
②÷①得:q=2,把q=2代入①得到a1=1,
则a7=26=64.
故答案为:64