$\"\"$

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The first row has $\"\"$ band member.

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The second row has $\"\"$ band members.

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The third row has $\"\"$ band members.

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So, $\"\"$ , $\"\"$ and $\"\"$ .

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Find the common difference.

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$\"\"$ .

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$\"\"$ .

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The common difference is $\"\"$ .

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(a)

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Find the number of band members in $\"\"$ row.

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Add $\"\"$ to the third term to find the fourth term, and so on.

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$\"\"$ .

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$\"\"$ .

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$\"\"$ .

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$\"\"$ .

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$\"\"$ .

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The number of band members in $\"\"$ row are $\"\"$ .

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$\"\"$

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(b)

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For an explicit formula, substitute $\"\"$ and $\"\"$ in the formula for the $\"\"$ term of an arithmetic sequence $\"\"$ .

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$\"\"$

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$\"\"$

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The explicit formula is $\"\"$ .

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For the recursive formula, state the first term $\"\"$ and then indicate that the next term is the sum of the previous term $\"\"$ and $\"\"$ .

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The recursive formula is $\"\"$ , $\"\"$ .

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$\"\"$

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(a) The number of band members in $\"\"$ row are $\"\"$ .

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(b)

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The explicit formula is $\"\"$ .

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The recursive formula is $\"\"$ , $\"\"$ .