How do you solve using the completing the square method #x^2-10x-4=0#?

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Answer 1 · 2016-02-26T13:29:04

#x = 5 +-sqrt2#

#x^2 - 10x - 4 = 0#

Notice 10x

This can be our #2ab# term

#(a-b)^ 2 = a^2 -2ab + b^2#

-2ab = -10x

ab =5x
We have a = x

b = 5

#x^2 - 10x + 5^2 - 5^2- 4 = 0#

#(x-5)^2 = 4 + 25 = 29#

#x - 5 = +-sqrt2#

#x = 5 +-sqrt2#