document.write( "Question 363323: For what value of k are the roots of 2x^2-8x+k=0 equal? \n" ); document.write( "

Algebra.Com's Answer #259027 by robertb(5830) $\"\"$ $\"About$

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$\"2x%5E2-8x%2Bk=0\"$ is the same as $\"x%5E2-4x%2Bk%2F2=0\"$ after division by 2. The product of the roots is $\"r%2Ar+=+r%5E2+=+k%2F2\"$ , while the sum of the roots is $\"r%2Br+=+2r+=+-%28-4%29+=+4\"$ . Thus $\"r+=+2\"$ , and $\"4+=+k%2F2\"$ , and thus $\"k+=+8\"$ . \n" ); document.write( "

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