document.write( "Question 1141757: A first number plus twice a second number is 11. Twice the first number plus
\n" ); document.write( "the second totals 31. Find the numbers. \n" ); document.write( "

Algebra.Com's Answer #762377 by ikleyn(52814) $\"\"$ $\"About$

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document.write( "From the condition, you have these two equations in two unknowns\r\n" );
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document.write( "     x + 2y = 11     (1)\r\n" );
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document.write( "    2x +  y = 31     (2)\r\n" );
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document.write( "From equation (1), express  x = 11 - 2y  and substitute it into the second equation. You will get\r\n" );
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document.write( "   2*(11-2y) + y = 31.\r\n" );
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document.write( "Simplify and solve for y\r\n" );
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document.write( "    22 - 4y + y = 31\r\n" );
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document.write( "    -3y         = 31 - 22\r\n" );
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document.write( "    -3y         = 9\r\n" );
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document.write( "      y         =  = -3.\r\n" );
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document.write( "Then  x = 11 - 2y = 11 - 2*(-3) = 11 + 6 = 17\r\n" );
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document.write( "ANSWER.  x = 17,  y = -3.\r\n" );
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