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高二必修五

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/04 03:24:49

解题思路: a9/(b5+b7)+a3/(b8+b4) =a9/2b6+a3/2b6 =a9+a3/2b6 =2a6/2b6 =(a1+a11)/(b1+b11) =11(a1+a11)/11(b1+b11) =[11(a1+a11)/2]/[11(b1+b11)/2] =S11/T11 =19/41
解题过程:
a9/(b5+b7)+a3/(b8+b4)

=a9/2b6+a3/2b6

=a9+a3/2b6
=2a6/2b6
=(a1+a11)/(b1+b11)
=11(a1+a11)/11(b1+b11)

=[11(a1+a11)/2]/[11(b1+b11)/2]
=S11/T11
=19/41