document.write( "Question 852261: evaluate (a + b).(a - b) if a = 2i - 3j + 5k and b = 3i + j - 2k \n" ); document.write( "
Algebra.Com's Answer #513278 by Edwin McCravy(20056)\"\" \"About 
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document.write( "(a + b)•(a - b) if a = 2i - 3j + 5k and b = 3i + j - 2k\r\n" );
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document.write( "a + b = (2i - 3j + 5k) + (3i + j - 2k) = 5i - 2j + 3k\r\n" );
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document.write( "a - b = (2i - 3j + 5k) - (3i + j - 2k) = -i - 4j + 7k\r\n" );
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document.write( "(a + b)•(a - b) = \r\n" );
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document.write( "(5i - 2j + 3k)•(-i - 4j + 7k) = (5)(-1)+(-2)(-4)+(3)(7) =\r\n" );
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document.write( "24\r\n" );
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document.write( "Edwin
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