Q11 of 34 Page 1

Solve the given equation by the method of completing the squares:

x2 + 12x – 45 = 0

x2 + 12x - 45 = 0


⇒ x2 + 2(x)(6) - 45 = 0


⇒ x2 + 2(x)(6) + (6)2 - (6)2 - 45 = 0


⇒ (x + 6)2 - 36 - 45 = 0


⇒ (x + 6)2 - 81 = 0


⇒ (x + 6)2 = 81


⇒ x + 6 = 9


⇒ x + 6 = 9 or x + 6 = -9


⇒ x = 3 or x = -15


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