factor the polynomial completely 
\n" );
document.write( "\r\n" );
document.write( "All feasible rational zeros are
the factors of 12 \r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "
,
,
,
,
,
, \r\n" );
document.write( "\r\n" );
document.write( "Also there are no sign changes so there are no positive zeros.\r\n" );
document.write( "\r\n" );
document.write( "So we begin by trying -1\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( " -1| 1 8 19 12\r\n" );
document.write( " | -1 -7 -12\r\n" );
document.write( " 1 7 12 0\r\n" );
document.write( "\r\n" );
document.write( "So x = -1 is a zero, so therefore (x + 1) is a factor.\r\n" );
document.write( "So now we have factored the original polynomial as\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "Now we factor the trinomial on the right and get:\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "That's it.\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" );
document.write( "