document.write( "Question 253163: y+2x=-1
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\n" ); document.write( "\n" ); document.write( "first equation:y plus 2x equals negative 1.
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Algebra.Com's Answer #185482 by Edwin McCravy(20060) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"system%28y%2B2x=-1%2C%0D%0Ay-4=-2x%29\"$
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document.write( "Solve either either equation for either letter.  I'll pick\r\n" );
document.write( "the easies letter to solve for, which is y because it only\r\n" );
document.write( "has an understood coefficient of 1 in either equation, whereas\r\n" );
document.write( "x has other coefficients.  I could pick either equation, \r\n" );
document.write( "so I'll just arbitrarily pick the first one to solve for y: \r\n" );
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document.write( "    y + 2x = -1\r\n" );
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document.write( "Add -2x to both sides:\r\n" );
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document.write( "    y + 2x = -1\r\n" );
document.write( "       -2x     -2x\r\n" );
document.write( "   ---------------\r\n" );
document.write( "    y      = -1-2x\r\n" );
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document.write( "Now substitute (-1-2x) for y in the OTHER equations.\r\n" );
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document.write( "Substitute  for y in\r\n" );
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document.write( "      y - 4 = -2x\r\n" );
document.write( " (1-2x) - 4 = -2x\r\n" );
document.write( " 1 - 2x - 4 = -2x \r\n" );
document.write( "    -3 - 2x = -2x\r\n" );
document.write( "        +2x   +2x\r\n" );
document.write( "    -------------\r\n" );
document.write( "    -3      = 0\r\n" );
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document.write( "Uh! Oh!  That's always false, -3 never equals 0, \r\n" );
document.write( "so there is no solution.\r\n" );
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document.write( "If you were to graph those two equations, you'd find\r\n" );
document.write( "that they were parallel and never had any points in common.\r\n" );
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document.write( "Here they are graphed:\r\n" );
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document.write( "Edwin

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