document.write( "Question 118532: For the quadratic equation x^2 + kx +7 =0, if 3+sqrt2 is a root, what is the value of k ?
\n" ); document.write( "I said 6 but my teacher marked it wrong. Please help me :)
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Algebra.Com's Answer #86640 by tutor_paul(519)\"\" \"About 
You can put this solution on YOUR website!
if something is a \"root,\" it means it is a value for x which satisfies the equation. So plug the root in for x ans solve for k:
\n" ); document.write( "\"x%5E2%2Bkx%2B7=0\"
\n" ); document.write( "\"%283%2Bsqrt%282%29%29%5E2%2Bk%283%2Bsqrt%282%29%29%2B7=0\"
\n" ); document.write( "\"9%2B6sqrt%282%29%2B2%2Bk%283%2Bsqrt%282%29%29%2B7=0\"
\n" ); document.write( "\"9%2B8.485%2B2%2Bk%284.414%29%2B7=0\"
\n" ); document.write( "\"k%284.414%29%2B26.485=0\"
\n" ); document.write( "\"k%284.414%29=-26.485\"
\n" ); document.write( "\"highlight%28k=-6%29\"
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