Algebra.Com's Answer #658616 by ikleyn(52780)![\"\"](\"/images/stars/stars-13.gif\")  
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document.write( "Let f(x)=x^4+2x^3-7x^2-20x-12
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document.write( "If -2 is a zero, factor f(x) completely
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document.write( "- please show how to factor it as well.
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document.write( "Figure. Plot f(x) =  \r
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document.write( "Let's apply grouping method.\r\n" );
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document.write( "f(x) = =  = \r\n" );
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document.write( "=  -  = \r\n" );
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document.write( "= -  = \r\n" );
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document.write( "=  = (now check the polynomial  for the roots. Check for x =1. \r\n" );
document.write( " See how I will extract this root by applying grouping again)\r\n" );
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document.write( "=  =  =  =\r\n" );
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document.write( "=  = =  =\r\n" );
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document.write( " Now you have to find the roots of the quadratic polynomial in parentheses.\r\n" );
document.write( " You can do it by many ways. Its roots are 2 and -3. Therefore\r\n" );
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document.write( "=  = (so you finally get)\r\n" );
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document.write( "=  .\r\n" );
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document.write( "Now identify the roots of the polynomial.\r\n" );
document.write( "Check the correspondence between the roots and the plot in the figure.\r\n" );
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document.write( "What method did I apply? - The grouping method.\r\n" );
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document.write( "What method did I apply? - The grouping method.\r\n" );
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document.write( "See also the lesson\r
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document.write( " - Solving polynomial equations of high degree by factoring\r
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document.write( "in this site.\r
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