SOLUTION: solve by completing the square x^2 + 8x - 9 = 0

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Question 394745: solve by completing the square
x^2 + 8x - 9 = 0
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 + 8x = 9

adding half of the x-term coefficient, squared ___ x^2 + 8x + (8/2)^2 = 9 + (8/2)^2

x^2 + 8x + 16 = 25 ___ (x + 4)^2 = 5^2

taking square root ___ x + 4 = ±5

x + 4 = 5 ___ x = 1

x + 4 = -5 ___ x = -9