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11 votes
11 votes
If using the method of completing the square to solve the quadratic equation x^2-19x+9=0x

2
−19x+9=0, which number would have to be added to "complete the square"?

User NielsNet
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1 Answer

26 votes
26 votes
19/2 = 9.5
(9.5)^2 = 90.25 = 9 + 81.25

x^2 - 19x + 9 = 0
x^2 - 19x + 90.25 - 81.25 = 0
(x - 9.5)^2 = 81.25
x - 9.5 = +/-sr(81.25)

I will let you finish from here
User Hacklikecrack
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