(2) \ \

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r² - 6r + 8 = 6 ( r² - 7r + 10 ) \ \

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r² - 6r + 8 = 6r² - 42r + 60 \ \

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6r² - 42r + 60 - r² + 6r - 8 = 0 \ \

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5r² - 36r + 52 = 0 \ \

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The solution is { 2 , 5.2 } \ \