$\"\"$

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The given evaluate $\"\"$ .

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Method 1

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Find the terms by replacing n with 7, 8, 9, 10, and 11.

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Substitute n values in $\"\"$

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$\"\"$ $\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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The sum of an arithmetic series $\"\"$ ,Where $\"\"$ is the first term and $\"\"$ is the nth term.

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Method 2

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There are 5 terms, $\"\"$ and $\"\"$ .

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The fifth terms of the arithmetic sequence $\"\"$ .

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$\"\"$ (Substitute $\"\"$ )

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$\"\"$ (Subtract: $\"\"$ )

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$\"\"$ (Multiply: $\"\"$ )

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$\"\"$ (Divide: $\"\"$ ) $\"\"$

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The sum of the arithmetic series is $\"\"$ .