We need to solve the equation: w² + 9 = 6w
⇒ w² - 6w + 9 = 0
⇒ w² - 3w - 3w + 9 = 0 (Breaking 6w such that their product is 9w²)
⇒ w × (w - 3) - 3 × (w - 3) = 0 (Extracting common factors)
⇒ (w - 3) × (w - 3) = 0
⇒ (w - 3)² = 0
⇒ w = 3
Hence, the correct answer is 3, which is the second option from the replacement set