document.write( "Question 1067896: how would you factor?\r
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Algebra.Com's Answer #683072 by ikleyn(52858) $\"\"$ $\"About$

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\n" ); document.write( "\n" ); document.write( "Let p(x) = 2x^4 - 5x^2 - 7.\r
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document.write( "The standard way is THIS:\r\n" );
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document.write( "1.  Introduce new variable u = x^2.   Then your original polynomial takes the form\r\n" );
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document.write( "    q(u) = 2u^2 - 5u - 7.\r\n" );
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document.write( "2.  Find its zeroes. For it, use the quadratic formula\r\n" );
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document.write( "     =  =  =  = .\r\n" );
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document.write( "    --->   =  = ,     = -1.\r\n" );
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document.write( "3.  So, the decomposition for q(u) is\r\n" );
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document.write( "    q(u) = 2u^2 - 5u - 7 = 2(u-(7/2))*(u-(-1)) = (2u-7)*(u+1).\r\n" );
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document.write( "    Therefore, the decomposition for the original polynomial is\r\n" );
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document.write( "    p(x) = 2x^4 - 5x^2 - 7 = (2x^2-7)*(x^2+1).\r\n" );
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document.write( "    You may factor it further\r\n" );
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document.write( "    p(x) = ,   if you want.\r\n" );
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