<PRE><B>Question 849059</B>
Find the common difference of the sequence 2, 7, 12, 17, 22, … What is the common difference ?
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In an arithmetic sequence the common difference
is the difference between any element and the element
immediately preceeding it.
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Example using your sequence: 
common difference:: 12-7 = 5
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Cheers,
Stan H.</PRE>