document.write( "Question 723369: When the 48 aliens first arrive on Earth they are all wearing either green or blue or both. 27 are wearing blue. The number that is wearing green is 8 more than that.
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\n" ); document.write( "\n" ); document.write( "Is this right? My CMT is next week! Please help! \n" ); document.write( "
Algebra.Com's Answer #443154 by Edwin McCravy(20063)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "No, that's incorrect.  Here's how to do it:\r\n" );
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document.write( "Draw two circles overlapping. One is labeled G for green, and\r\n" );
document.write( "the other labeled B for blue. That makes 3 regions.\r\n" );
document.write( "There are x in the region on the left, there are\r\n" );
document.write( "y in the region in the middle, and z in the region on\r\n" );
document.write( "the right.\r\n" );
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document.write( "x are wearing just green, y are wearing both green and \r\n" );
document.write( "blue, and z are wearing just blue.\r\n" );
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document.write( "Since there are 48 aliens, that tells us that\r\n" );
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document.write( "x + y + z = 48\r\n" );
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document.write( "We are told \r\n" );
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document.write( "Notice that some of those 27 are wearing blue only\r\n" );
document.write( "(these are the z in the region on the far right, and \r\n" );
document.write( "the rest of those 27 are in the middle region who also \r\n" );
document.write( "are wearing green, so\r\n" );
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document.write( "Since 27 are wearing blue, that tells us that\r\n" );
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document.write( "y + z = 27\r\n" );
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document.write( "Then we are told:\r\n" );
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\n" ); document.write( "The number that are wearing green is 8 more than that.
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document.write( "8 more than 27 is 27+8 or 35. Notice that some of those \r\n" );
document.write( "35 are wearing green only (these are the x in the region \r\n" );
document.write( "on the far left, and the rest of those 35 are in the middle \r\n" );
document.write( "region who also wear blue, so\r\n" );
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document.write( "x + y = 35\r\n" );
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document.write( "That gives us the system of equations:\r\n" );
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document.write( "(1)    x + y + z = 48\r\n" );
document.write( "(2)        y + z = 27\r\n" );
document.write( "(3)    x + y     = 35\r\n" );
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document.write( "Subtract equation (2) from equation (1) term by term\r\n" );
document.write( "and get\r\n" );
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document.write( "       x         = 21\r\n" );
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document.write( "Subtract equation (3) from equation (1) term by term\r\n" );
document.write( "and get\r\n" );
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document.write( "               z = 13\r\n" );
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document.write( "Substitute that in equation (2)\r\n" );
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document.write( "           y + z = 27\r\n" );
document.write( "          y + 13 = 27\r\n" );
document.write( "               y = 14\r\n" );
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document.write( "So x = 21, y = 14, z = 13.\r\n" );
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document.write( "The question asks how many are just wearing green.\r\n" );
document.write( "That's the value of x, which is 21.\r\n" );
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document.write( "Edwin
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