作业帮有两个等差数列{an],{bn]满足（a1+a2+a3+…an）/（b1+b2+b3+…bn）=（7n+2）/（n+3）,求a5/b5
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![有两个等差数列{an],{bn]满足（a1+a2+a3+…an）/（b1+b2+b3+…bn）=（7n+2）/（n+3）,求a5/b5](/uploads/image/z/2430616-40-6.jpg?t=%E6%9C%89%E4%B8%A4%E4%B8%AA%E7%AD%89%E5%B7%AE%E6%95%B0%E5%88%97%7Ban%5D%2C%7Bbn%5D%E6%BB%A1%E8%B6%B3%EF%BC%88a1%2Ba2%2Ba3%2B%E2%80%A6an%EF%BC%89%2F%EF%BC%88b1%2Bb2%2Bb3%2B%E2%80%A6bn%EF%BC%89%3D%EF%BC%887n%2B2%EF%BC%89%2F%EF%BC%88n%2B3%EF%BC%89%2C%E6%B1%82a5%2Fb5)
有两个等差数列{an],{bn]满足（a1+a2+a3+…an）/（b1+b2+b3+…bn）=（7n+2）/（n+3）,求a5/b5
有两个等差数列{an],{bn]满足（a1+a2+a3+…an）/（b1+b2+b3+…bn）=（7n+2）/（n+3）,求a5/b5
有两个等差数列{an],{bn]满足（a1+a2+a3+…an）/（b1+b2+b3+…bn）=（7n+2）/（n+3）,求a5/b5
a5/b5
=(2a5)/(2b5)
=(a1+a9)/(b1+b9)
=[(a1+a9)×9÷2]/[(b1+b9)×9÷2]
=(a1+a2+a3+...+a9)/(b1+b2+b3+...+b9)
=(7×9+2)/(9+3)
=65/12