document.write( "Question 934997: For which values of k are 2k, 5k+2, and 20k-4 consecutive terms of a geometric sequence? \n" ); document.write( "

Algebra.Com's Answer #568050 by ewatrrr(24785) $\"\"$ $\"About$

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$\"%285k%2B2%29%2F2k+=+%2820k-4%29%2F%285k%2B2%29\"$
\n" ); document.write( "2k(20k-4) = (5k+2)(5k+2) = 25K^2 + 20k + 4
\n" ); document.write( "40k^2 - 8k = 25K^2 + 20k + 4
\n" ); document.write( "15k^2 - 28k - 4 = 0
\n" ); document.write( " $\"x+=+%2828+%2B-+sqrt%28+1024+%29%29%2F%2830%29+\"$
\n" ); document.write( " $\"x+=+%2828+%2B-+32%29%2F%2830%29+\"$
\n" ); document.write( "k = 2, -2/15
\n" ); document.write( "and...checking
\n" ); document.write( "2k, 5k+2, and 20k-4
\n" ); document.write( "4, 12, 36, ...
\n" ); document.write( "-4/15, 4/3, -20/3,... \n" ); document.write( "

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