document.write( "Question 77334: Q.1) If a, b, c, are real numbers such that a2+2b=6, b2+4c= -7 and c2+6a= -13, then the value of a2+b2+c2 is equal to :
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Algebra.Com's Answer #55460 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
Q.1) If a, b, c, are real numbers such that a²+2b=6, b²+4c= -7 and c²+6a= -13,\r\n" );
document.write( "then the value of a²+b²+c² is equal to :\r\n" );
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document.write( "a²+2b=6\r\n" );
document.write( "b²+4c= -7\r\n" );
document.write( "c²+6a= -13\r\n" );
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document.write( "I don't believe this one has a solution in real numbers. It doesn't\r\n" );
document.write( "according to my graphing calculator. Are you sure you copied it right?\r\n" );
document.write( "Maybe you didn't mean a² by a2. Did you?\r\n" );
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document.write( "Q.2) If x, y and z are positive integers with xy= 24, xz= 48 and yz=72,\r\n" );
document.write( "     then x+y+z is:\r\n" );
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document.write( "(A) 18 (B) 19 (C) 20 (D) 22\r\n" );
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document.write( "This one is straight-forward:\r\n" );
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document.write( "xy = 24\r\n" );
document.write( "xz = 48\r\n" );
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document.write( "Divide equals by equals\r\n" );
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document.write( " xy     24\r\n" );
document.write( "---- = ----\r\n" );
document.write( " xz     48\r\n" );
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document.write( " 1       1\r\n" );
document.write( " xy     24\r\n" );
document.write( "---- = ----\r\n" );
document.write( " xz     48\r\n" );
document.write( " 1       2\r\n" );
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document.write( " y     1\r\n" );
document.write( "--- = ---\r\n" );
document.write( " z     2\r\n" );
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document.write( "Cross-multiply\r\n" );
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document.write( " z = 2y\r\n" );
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document.write( "Substitute that in\r\n" );
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document.write( "yz = 72\r\n" );
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document.write( "y(2y) = 72\r\n" );
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document.write( "  2y² = 72\r\n" );
document.write( "   y² = 36\r\n" );
document.write( "    y = 6\r\n" );
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document.write( "Substitute that in\r\n" );
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document.write( "    yz = 72\r\n" );
document.write( "    6z = 7\r\n" );
document.write( "     z = 12 \r\n" );
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document.write( "Substitute y = 6 in\r\n" );
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document.write( "    xy = 24\r\n" );
document.write( "  x(6) = 24 \r\n" );
document.write( "    6x = 24\r\n" );
document.write( "     x = 4 \r\n" );
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document.write( "x = 4, y = 6, z = 12\r\n" );
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document.write( "so x + y + z = 4 + 6 + 12 = 22 choice (D)\r\n" );
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document.write( "Edwin
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