document.write( "Question 482586: If a + b = 5 and ab = 6 , then find the value of \r
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Algebra.Com's Answer #330345 by Edwin McCravy(20060)\"\" \"About 
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document.write( "If  a + b = 5  and  ab = 6 , then find the value of \r\n" );
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document.write( "4(a² - b²) – a³ + b³,    if a > b .\r\n" );
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document.write( "Solve the system of equations:\r\n" );
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document.write( "ìa + b = 5 \r\n" );
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document.write( "î   ab = 6\r\n" );
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document.write( "Solve the first for b:\r\n" );
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document.write( "              a + b = 5\r\n" );
document.write( "                  b = 5 - a\r\n" );
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document.write( "Substitute 5 - a for b in the second equation of the system:\r\n" );
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document.write( "                 ab = 6\r\n" );
document.write( "           a(5 - a) = 6\r\n" );
document.write( "            5a - a² = 6\r\n" );
document.write( "       -a² + 5a - 6 = 0 \r\n" );
document.write( "        a² - 5a + 6 = 0\r\n" );
document.write( "     (a - 3)(a - 2) = 0\r\n" );
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document.write( "     a - 3 = 0;   a - 2 = 0\r\n" );
document.write( "         a = 3;       a = 2\r\n" );
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document.write( "     b = 5 - a    b = 5 - a \r\n" );
document.write( "     b = 5 - 3    b = 5 - 2\r\n" );
document.write( "     b = 2        b = 3\r\n" );
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document.write( "There are two solutions (a,b) = (3,2) and (a,b) = (2,3)\r\n" );
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document.write( "But we are told that a > b so we choose the first and\r\n" );
document.write( "discard the second, so a=3 and b=2 \r\n" );
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document.write( "Therefore the value of\r\n" );
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document.write( "4(a² - b²) – a³ + b³   is\r\n" );
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document.write( "4(3² - 2²) – 3³ + 2³\r\n" );
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document.write( " 4(9 - 4) - 27 + 8 \r\n" );
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document.write( "     4(5) - 19 \r\n" );
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document.write( "       20 - 19\r\n" );
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document.write( "          1\r\n" );
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document.write( "Edwin

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