document.write( "Question 973174: x^1/2 + y = 7
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Algebra.Com's Answer #853956 by MathTherapy(10801)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "x^1/2 + y = 7\r\n" );
document.write( "x + y^1/2 = 11\r\n" );
document.write( "Find the value of x and y\r\n" );
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document.write( "\"matrix%282%2C1%2C+%22+%22%2C+x%5E%281%2F2%29+%2B+y+=+7%29\"____\"sqrt%28x%29+%2B+y+=+7\" \r\n" );
document.write( "                                   \"sqrt%28x%29+=+7++-++y\"\r\n" );
document.write( "                              \"%28sqrt%28x%29%29%5E2+=+%287++-++y%29%5E2\"\r\n" );
document.write( "                                     \"x+=+49++-++14y+%2B+y%5E2\" ----- eq (i)\r\n" );
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document.write( "                              \"x+%2B+sqrt%28y%29+=+11\"\r\n" );
document.write( "                                     \"x+=+11+-+sqrt%28y%29\" ----- eq (ii)\r\n" );
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document.write( "We then get: \"49++-++14y+%2B+y%5E2+=+11+-+sqrt%28y%29\"\r\n" );
document.write( "         \"y%5E2+%2B+sqrt%28y%29+-+14y+%2B+49+-+11+=+0\"\r\n" );
document.write( "                \"y%5E2+%2B+sqrt%28y%29+-+14y+%2B+38+=+0\"\r\n" );
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document.write( "                                 Let \"sqrt%28y%29+=+t\"\r\n" );
document.write( "              Then: \"system%28%28sqrt%28y%29%29%5E2+=+t%5E2%2C+y+=+t%5E2%2C+y%5E2+=+%28t%5E2%29%5E2+=+t%5E4%29\"\r\n" );
document.write( "                        \"y%5E2+%2B+sqrt%28y%29+-+14y+%2B+38+=+0\" then becomes: \r\n" );
document.write( "                        \"t%5E4+%2B+t+-+14t%5E2+%2B+38+=+0\"\r\n" );
document.write( "                        \"t%5E4+-+14t%5E2+%2B+t+%2B+38+=+0\"\r\n" );
document.write( "Using the RATIONAL ROOT THEOREM, we find that a root of the above equation is: t = 2, which makes its\r\n" );
document.write( "FACTOR, t - 2. When divided by t - 2, using LONG DIVISION of POLYNOMIALS, or using SYNTHETIC DIVISION,\r\n" );
document.write( "the other factor of \"t%5E4++-++14t%5E2+%2B+t+%2B+38\", besides t - 2, is: \"t%5E3+%2B+2t%5E2+-+10t+-+19\".\r\n" );
document.write( "From this, we find another REAL solution being approximately 3.13131. The other 2 are negative (< 0) and\r\n" );
document.write( "so, MUST be REJECTED/IGNORED, since \"sqrt%28y%29+=+t\" CANNOT have a negative (< 0) value for t. \r\n" );
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document.write( "I will continue with the REAL INTEGER value, 2.\r\n" );
document.write( "     \"sqrt%28y%29+=+t+=+2\" ---- Back-substituting t = 2 for \"sqrt%28y%29\"\r\n" );
document.write( "\"%28sqrt%28y%29%29%5E2+=+y+=+t%5E2+=+2%5E2+=+4\"\r\n" );
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document.write( "       \"x+=+11+-+sqrt%28y%29\" ----- eq (ii)\r\n" );
document.write( "        x = 11 - 2 ----- Substituting 2 for \"sqrt%28y%29\" in eq (ii)\r\n" );
document.write( "        x = 9\r\n" );
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document.write( "So, the ONLY INTEGER-solution set is: (x, y) = (9, 4). I'll let you substitute the other REAL VALUE, 3.13131\r\n" );
document.write( "for t, to determine the other SOLUTION-SET.
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