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document.write( "First use the slope formula:\r\n" );
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document.write( "where (x1,y1) = (-9,7)\r\n" );
document.write( "and where (x2,y2) = (9,-1)\r\n" );
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document.write( "Now that you have the slope, use the point-slope formula:\r\n" );
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document.write( "where (x1,y1) = (-9,7)\r\n" );
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document.write( "[Don't substitute anything for variables x and y, but leave them\r\n" );
document.write( "as they are and just substitute for x1 and y1.]\r\n" );
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document.write( "That's the slope y-intercept form. If\r\n" );
document.write( "you like you can get it into general form.\r\n" );
document.write( "Multiply through by 9 to clear the fraction:\r\n" );
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document.write( "Edwin
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document.write( "![\"\"](\"/images/stars/stars-13.gif\")
