$\"\"$

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The given evaluate $\"\"$ .

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Method 1

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Find the terms by replacing n with 3, 4, 5, 6, and 7.

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Substitute n values in $\"\"$ . $\"\"$ $\"\"$

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$\"\"$

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= 95

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$\"\"$

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The sum of an arithmetic series $\"\"$ .

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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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$\"\"$

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

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$\"\"$ (Add: 13 + 25 = 38)

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

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

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The sum of the arithmetic series is 95.