document.write( "Question 448793: A first number plus twice a second number is 8. Twice the first number, plus the second number totals 25. Find the numbers. \n" ); document.write( "

Algebra.Com's Answer #853359 by ikleyn(53479) $\"\"$ $\"About$

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\n" ); document.write( "A first number plus twice a second number is 8. Twice the first number, plus the second number totals 25.
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\n" ); document.write( "\n" ); document.write( " There is very easy and effective way to solve it - practically mentally, in the head.\r
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document.write( "The equations are\r\n" );
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document.write( "     x + 2y =  8    (1)\r\n" );
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document.write( "    2x +  y = 25    (2)\r\n" );
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document.write( "Add the equations\r\n" );
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document.write( "    3x + 3y = 33,\r\n" );
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document.write( "hence\r\n" );
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document.write( "    x + y = 11.     (3).\r\n" );
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document.write( "Compare (1) and (3).  It should be clear from the comparison that  y = -3.\r\n" );
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document.write( "Next, compare equations (2) and (3).  It should be clear for the comparison that  x = 14.\r\n" );
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document.write( "Now check these values and makes sure that they satisfy equations.\r\n" );
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