在两个等差数列{an}和{bn},满足(a1+a2+a3+…+an)/(b1+b2+b3+…bn)=(7n+2)/(n+3,求a5/b5)
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![在两个等差数列{an}和{bn},满足(a1+a2+a3+…+an)/(b1+b2+b3+…bn)=(7n+2)/(n+3,求a5/b5)](/uploads/image/z/3622985-17-5.jpg?t=%E5%9C%A8%E4%B8%A4%E4%B8%AA%E7%AD%89%E5%B7%AE%E6%95%B0%E5%88%97%7Ban%7D%E5%92%8C%7Bbn%7D%2C%E6%BB%A1%E8%B6%B3%28a1%2Ba2%2Ba3%2B%E2%80%A6%2Ban%29%2F%EF%BC%88b1%2Bb2%2Bb3%2B%E2%80%A6bn%EF%BC%89%3D%287n%2B2%29%2F%28n%2B3%2C%E6%B1%82a5%2Fb5%29)
在两个等差数列{an}和{bn},满足(a1+a2+a3+…+an)/(b1+b2+b3+…bn)=(7n+2)/(n+3,求a5/b5)
在两个等差数列{an}和{bn},满足(a1+a2+a3+…+an)/(b1+b2+b3+…bn)=(7n+2)/(n+3,求a5/b5)
在两个等差数列{an}和{bn},满足(a1+a2+a3+…+an)/(b1+b2+b3+…bn)=(7n+2)/(n+3,求a5/b5)
a1+a2+...+a9=(a1+a9)+(a2+a8)+(a3+a7)+(a4+a6)+a5=9a5
b1+b2+...+b9=(b1+b9)+...+(b4+b6)+b5=9b5
可见,取n=9
(7*9+2)/(9+3)=(9a5)/(9b5)=a5/b5
所以a5/b5=65/12