document.write( "Question 944201: if a,b,c are in H.P then (1/a + 1/b - 1/c)(1/b + 1/c - 1/a)=? \n" ); document.write( "
Algebra.Com's Answer #576187 by Edwin McCravy(20056)\"\" \"About 
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document.write( "Since a,b,c are in H.P., then 1/a,1/b,1/c are in A.P., so 1/b-1/a=1/c-1/b,\r\n" );
document.write( "or 1/c = 2/b-1/a, substituting that for 1/c in\r\n" );
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document.write( " (1/a + 1/b - 1/c)(1/b + 1/c - 1/a) \r\n" );
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document.write( "ans simplifying, gives\r\n" );
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document.write( "((2b-a)(3a-2b))/(a^2b^2)\r\n" );
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document.write( "which is nothing special at all.\r\n" );
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document.write( "Edwin
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