document.write( "Question 1153597: Determine the intersection of lines
\n" ); document.write( "r1=(2,-1,-1)+ t(1,2,-1)and
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Algebra.Com's Answer #775928 by AnlytcPhil(1806)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Equate x-coordinates:\r\n" );
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document.write( "\"2%2Bt=-1-2u\"\r\n" );
document.write( "\"t%2B2u=-3\"\r\n" );
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document.write( "Equate y-coordinates\r\n" );
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document.write( "\"-1%2B2t=-1-u\"\r\n" );
document.write( "\"2t%2Bu=0\"\r\n" );
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document.write( "Solve the system:\r\n" );
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document.write( "\"system%28t%2B2u=-3%2C2t%2Bu=0%29\"\r\n" );
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document.write( "Solution: (t,u) = (1,-2)  \r\n" );
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document.write( "Equate z-coordinates\r\n" );
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document.write( "\"-1-t=1%2Bu\"\r\n" );
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document.write( "See if that is consistent with (t,u) = (1,-2)\r\n" );
document.write( "by substituting it:\r\n" );
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document.write( "\"-1-1=1%2B%28-2%29\"\r\n" );
document.write( "\"-2=-1\"\r\n" );
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document.write( "No it's not consistent, so the lines do not intersect.\r\n" );
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document.write( "Edwin
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