document.write( "Question 724863: a) Determine the sets A, B where A − B = {1, 3, 7, 11}, B – A= {2, 6, 8}, and A ∩ B= {4, 9}.
\n" ); document.write( "b) Determine the sets C, D where C − D = {1, 2, 4}, D − C = {7, 8}, and C ∪ D= {1, 2, 4, 5, 7, 8, 9}
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Algebra.Com's Answer #443923 by AnlytcPhil(1806) $\"\"$ $\"About$

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\n" ); document.write( "Determine the sets A, B where \r
\n" ); document.write( "\n" ); document.write( "A - B = {1, 3, 7, 11}
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\r\n" );
document.write( "From that we have:\r\n" );
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document.write( " 1 ∈ A,   1 ∉ B\r\n" );
document.write( " 3 ∈ A,   3 ∉ B\r\n" );
document.write( " 7 ∈ A,   7 ∉ B\r\n" );
document.write( "11 ∈ A,  11 ∉ B \r\n" );
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document.write( "B - A= {2, 6, 8}, \r\n" );
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document.write( "From that we have:\r\n" );
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document.write( " 2 ∈ B,   2 ∉ A\r\n" );
document.write( " 6 ∈ B,   6 ∉ A\r\n" );
document.write( " 8 ∈ B,   8 ∉ A\r\n" );
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document.write( "A ∩ B = {4, 9}\r\n" );
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document.write( "From that we have:\r\n" );
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document.write( " 4 ∈ A,   4 ∈ B,   9 ∈ A,   9 ∈ B \r\n" );
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document.write( "So we end up with\r\n" );
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document.write( "A = {1,3,7,11,4,9}, B = {2,6,8,4,9}\r\n" );
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document.write( "----------------------------------------\r\n" );
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\n" ); document.write( " C - D = {1, 2, 4},
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\r\n" );
document.write( "From that we have:\r\n" );
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document.write( " 1 ∈ C,   1 ∉ D\r\n" );
document.write( " 2 ∈ C,   2 ∉ D\r\n" );
document.write( " 4 ∈ C,   4 ∉ D\r\n" );
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document.write( "D − C = {7, 8}, \r\n" );
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document.write( "From that we have:\r\n" );
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document.write( " 7 ∈ D,   7 ∉ C\r\n" );
document.write( " 8 ∈ D,   8 ∉ C\r\n" );
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document.write( "C ∪ D = {1, 2, 4, 5, 7, 8, 9}\r\n" );
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document.write( "Since 5 and 9 are not in either C - D or in D - C,\r\n" );
document.write( "they must be elements of both sets, since they were\r\n" );
document.write( "removed in both cases of set subtraction.  Therefore\r\n" );
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document.write( "C = {1,2,4,5,9},  D = {7,8,5,9}\r\n" );
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document.write( "Edwin

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