$\"\"$

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The given values are $\"\"$ .

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Where $\"\"$ is the first term and $\"\"$ is the common difference.

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

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

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

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Apply division property of equality: a = b then $\"\"$ .

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$\"\"$ (Divide each side by 4)

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$\"\"$ (Cancel common terms)

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

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Apply subtraction property of equality: a = b then $\"\"$ .

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$\"\"$ (Subtract 36 from each side)

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

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Find the common difference d, substitute $\"\"$ , n = 8 and $\"\"$ in $\"\"$ .

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$\"\"$

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

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

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Apply multiplication property of equality: a = b then $\"\"$ .

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$\"\"$ (Multiply each side by $\"\"$ )

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$\"\"$ (Cancel common term)

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

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Apply addition property of equality: a = b then $\"\"$ .

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$\"\"$ (Add 12 to each side)

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$\"\"$ (Add: 30 + 12 = 42)

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Apply division property of equality: a = b then $\"\"$ .

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$\"\"$ (Divide each side by 7)

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$\"\"$ (Cancel common terms)

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d = 6 (Divide: $\"\"$ )

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The 1st term is $\"\"$ and 2nd term is a + d = $\"\"$ .

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3rd term is a + 2d = $\"\"$ . $\"\"$

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The first three terms of the series is $\"\"$ .