document.write( "Question 1208779:
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Algebra.Com's Answer #847222 by Shin123(626) $\"\"$ $\"About$

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Note that a quadratic has a repeated root if and only if the discriminant of it is 0. The discriminant of this quadratic is $\"k%5E2-4%281%29%284%29=k%5E2-16\"$ . Therefore, we must have $\"k%5E2-16=0\"$ , so $\"k=4\"$ or $\"k=-4\"$ . We can check that both of these indeed work, $\"x%5E2%2B4x%2B4=%28x%2B2%29%5E2\"$ , and $\"x%5E2-4x%2B4=%28x-2%29%5E2\"$ . \n" ); document.write( "

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