Completing the square in quadratics of the form x^2 + bx + c

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Originally Posted by Siron

Can you be more clear about your question? We've found the complete square of which is .
Where are you stuck? What do you not understand? ...

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I thought the completed square was the first part that was worked out.

x^2 - 8x - 5

(x - 4)^2 - 16 without the - 5 being added, why am I wrong?

Completing the square is a technique for converting a quadratic polynomial of the form into the form where are constants.
So that's what we've done here and notice .

Does this answers your questions? ...

If you want to have a confirmation take a look here:
http://www.wolframalpha.com/input/?i=complete+the+square+of+x^2-8x-5