document.write( "Question 49779: Solve using any method:
\n" ); document.write( "2x-7y=540
\n" ); document.write( "14x+3y=120 \n" ); document.write( "
Algebra.Com's Answer #33047 by AnlytcPhil(1806)\"\" \"About 
You can put this solution on YOUR website!
Solve using any method:\r\n" );
document.write( " 2x - 7y = 540\r\n" );
document.write( "14x + 3y = 120\r\n" );
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document.write( "Since there are no 1 or -1 \r\n" );
document.write( "coefficients, the easiest way \r\n" );
document.write( "is by elimination.\r\n" );
document.write( "(This is sometimes called\r\n" );
document.write( "\"addition method\" or the\r\n" );
document.write( "\"addition-subtraction method\".)\r\n" );
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document.write( "Eliminate x by multiplying the\r\n" );
document.write( "first equation thru by -7 and the\r\n" );
document.write( "bottom equation thru by 1. Then\r\n" );
document.write( "add vertically:\r\n" );
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document.write( "-7[ 2x - 7y = 540]\r\n" );
document.write( " 1[14x + 3y = 120]\r\n" );
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document.write( "  -14x + 49y = -3780\r\n" );
document.write( "   14x +  3y =   120\r\n" );
document.write( "--------------------\r\n" );
document.write( "         52y = -3660 \r\n" );
document.write( "           y = -915/13\r\n" );
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document.write( "That is the value for y\r\n" );
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document.write( "However it is very difficult to\r\n" );
document.write( "substitute such a god-awful \r\n" );
document.write( "fraction as that.  So start over\r\n" );
document.write( "and eliminate y by multiplying the\r\n" );
document.write( "first equation thru by 3 and the\r\n" );
document.write( "bottom equation thru by 7. Then\r\n" );
document.write( "add vertically:\r\n" );
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document.write( "3[ 2x - 7y = 540]\r\n" );
document.write( "7[14x + 3y = 120]\r\n" );
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document.write( "   6x - 21y = 1620\r\n" );
document.write( "  98x + 21y =  840\r\n" );
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document.write( " 104x       = 2460\r\n" );
document.write( "          x = 2460/104\r\n" );
document.write( "          x = 615/26\r\n" );
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document.write( "That's the value of x\r\n" );
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document.write( "Even though they are\r\n" );
document.write( "terrible fractions, they\r\n" );
document.write( "caused no difficulty since\r\n" );
document.write( "instead of substituting,\r\n" );
document.write( "we started over and \r\n" );
document.write( "eliminated the other variable.\r\n" );
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document.write( "Answer (x,y,) = (615/26, -915/13)\r\n" );
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document.write( "Edwin
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