In order to factor  , first we need to ask ourselves: What two numbers multiply to 8 and add to -9? Lets find out by listing all of the possible factors of 8
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document.write( " Factors:
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document.write( " 1,2,4,8,
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document.write( " -1,-2,-4,-8,List the negative factors as well. This will allow us to find all possible combinations
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document.write( " These factors pair up to multiply to 8.
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document.write( " 1*8=8
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document.write( " 2*4=8
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document.write( " (-1)*(-8)=8
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document.write( " (-2)*(-4)=8
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document.write( " note: remember two negative numbers multiplied together make a positive number
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document.write( " Now which of these pairs add to -9? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -9
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document.write( " | First Number | | | Second Number | | | Sum | | 1 | | | 8 | || | 1+8=9 | | 2 | | | 4 | || | 2+4=6 | | -1 | | | -8 | || | -1+(-8)=-9 | | -2 | | | -4 | || | -2+(-4)=-6 | We can see from the table that -1 and -8 add to -9.So the two numbers that multiply to 8 and add to -9 are: -1 and -8\r\n" );
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document.write( " Now we substitute these numbers into a and b of the general equation of a product of linear factors which is:\r\n" );
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document.write( "  substitute a=-1 and b=-8\r\n" );
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document.write( " So the equation becomes:\r\n" );
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document.write( " (x-1)(x-8)\r\n" );
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document.write( " Notice that if we foil (x-1)(x-8) we get the quadratic again\n" );
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document.write( "So we now have\r
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document.write( " or  \r
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document.write( "So our possible solutions are
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document.write( " or
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document.write( "However we must check these answers first\r
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document.write( "Check:
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document.write( "Plug in x=1
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document.write( "Since this is not true, we must discard the solution of x=1\r
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document.write( "Plug in x=8\r
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document.write( " works. This is our only solution\r
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document.write( "So our only solution is \r
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document.write( "x=8\r
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