Let's go through Sehyr's work step by step to identify where she made the error and find the correct solution to the equation \( w^2 - 7 = 11 \).
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Original equation: \[ w^2 - 7 = 11 \]
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Adding 7 to both sides: Sehyr correctly applies the Addition Property of Equality: \[ w^2 - 7 + 7 = 11 + 7 \] This simplifies to: \[ w^2 = 18 \]
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Error in division: After getting \( w^2 = 18 \), Sehyr incorrectly wrote: \[ w^2 = 182 \] This is not correct; she should have written \( w^2 = 18 \).
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Taking the square root: To solve for \( w \), we take the square root of both sides: \[ w = \sqrt{18} \quad \text{or} \quad w = -\sqrt{18} \]
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Simplifying \(\sqrt{18}\): \[ \sqrt{18} = \sqrt{9 \cdot 2} = 3\sqrt{2} \]
Thus, the solutions to the equation are: \[ w = 3\sqrt{2} \quad \text{or} \quad w = -3\sqrt{2} \]
Therefore, the correct solution to the equation \( w^2 - 7 = 11 \) is: \[ w = \pm 3\sqrt{2} \]