\"\"

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The given values \"\".

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Apply alternative formula for sum of a geometric series \"\".

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Where \"\" is first term and r is common ratio.

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\"\"          (Substitute \"\")

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\"\"             (Product of  two same signs is positive)\"\"

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\"\"             (Add denominator: \"\")

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

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\"\"                            (Add: \"\")

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

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The value of \"\".