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Cameron L
Cameron L asked in Science & MathematicsMathematics · 1 decade ago

Factoring out imaginary numbers?

Ok, so I understand this:

x^2 + 4 = 0

x^2 = -4

x = (plus or minus) sqrt(-4)

x = (plus or minus) 2i

So, the question I'm having problems with is this:

x^2 + 2x +5 = 0

x^2 = -2x - 5

x = (plus or minus) sqrt(-2x-5)

Does it come out to this?:

x= sqrt(2x+t5), or x= sqrt(2x-5), or neither?

Thanks for any help.

2 Answers

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  • Anonymous
    1 decade ago
    Favorite Answer

    You haven't solved the equation for x. For a quadratic like x^2 + 2x + 5 = 0, you should be using completing the square or the quadratic forumula.

  • Anonymous
    5 years ago

    This factors over the reals. x² + 20 would factor over the imaginaries. x² − 20 = (x + √20)(x − √20) = (x + 2√5)(x − 2√5)

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