document.write( "Question 1139594: Find two positive numbers x and y such that they add to 20 and x^2 + y^2 is a minimum. \n" ); document.write( "
Algebra.Com's Answer #760076 by ikleyn(52781)\"\" \"About 
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document.write( "\"x%5E2\" + \"y%5E2\" = \"x%5E2\" + \"%2820-x%29%5E2\" = \"x%5E2+%2B+400+-+40x+%2B+x%5E2\" = \"2x%5E2+-+40x+%2B400\".\r\n" );
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document.write( "The minimum is achieved at  x = \"-b%2F%282a%29\" = \"-%28-40%29%2F%282%2A2%29\" = \"40%2F4\" = 10.\r\n" );
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document.write( "ANSWER.  x = y = 10.\r\n" );
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\n" ); document.write( "\n" ); document.write( "On finding the maximum/minimum of a quadratic function see the lessons\r
\n" ); document.write( "\n" ); document.write( "    - HOW TO complete the square to find the minimum/maximum of a quadratic function\r
\n" ); document.write( "\n" ); document.write( "    - Briefly on finding the minimum/maximum of a quadratic function\r
\n" ); document.write( "\n" ); document.write( "    - HOW TO complete the square to find the vertex of a parabola\r
\n" ); document.write( "\n" ); document.write( "    - Briefly on finding the vertex of a parabola\r
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\n" ); document.write( "\n" ); document.write( "Also,  you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this textbook under the topic \"Finding minimum/maximum of quadratic functions\". \r
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\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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