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已知点(n,an)(n∈N*)都在直线3x-y-24=0上,那么在数列an中有a...
已知点(n,an)(n∈N*)都在直线3x-y-24=0上,那么在数列an中有a7+a9=( )
A.a7+a9>0
B.a7+a9<0
C.a7+a9=0
D.a7•a9=0
考点分析:
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如图所示,F
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