Question 73561
{{{x^2 - 8 = 0}}}
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For this problem the easiest way to do it is to add 8 to both sides.  Then the problem becomes
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{{{x^2 = 8}}}
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Then just take the square root of both sides and you get 
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{{{x = sqrt(8)}}} and {{{x = -sqrt(8)}}}
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The square root of 8 can be simplified by factoring it into {{{sqrt(4*2)}}} which can then
be written as {{{sqrt(4)*sqrt(2)}}}. Since {{{sqrt(4)= 2 }}} you can substitute 2 for {{{sqrt(4)}}} 
to get that {{{sqrt(8) = 2*sqrt(2)}}}
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So the answer simplifies to:
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{{{x = 2*sqrt(2)}}} and {{{x = -2*sqrt(2)}}}
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There are no complex factors involved here.
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The only thing you have to be careful with in solving this problem is to recognize
that the value for x has to be either plus or minus because if you square them both the
plus and minus values will return a positive value.  Squaring:
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{{{2*sqrt(2)}}} and {{{-2*sqrt(2)}}} 
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will both compute to be +8.  Therefore either of these will satisfy the equation.  
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Hope this helps you with this problem.