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Arithmetic Sequences

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Source: — Problem Solving |
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by ColumbiaVC » Wed Aug 10, 2011 4:20 pm
a3=4; a5=20
an=((an-1)+(an-2))/2

a5=((a3)+(a4))/2
=> 20=((4)+(a4))/2
=> a4=36

a6=((a4)+(a5))/2
=> a6=(36+20)/2
=> a6=28
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