document.write( "Question 1179778: During one month, a homeowner used 300 units of electricity and 140 units of gas for a total cost of $106.20. The next month, 250 units of electricity and 250 units of gas were used for a total cost of $112.50. Find the cost per unit of gas. \n" ); document.write( "
Algebra.Com's Answer #809367 by ikleyn(52780)\"\" \"About 
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\n" ); document.write( "During one month, a homeowner used 300 units of electricity and 140 units of gas
\n" ); document.write( "for a total cost of $106.20. The next month, 250 units of electricity and 250 units of gas
\n" ); document.write( " were used for a total cost of $112.50. Find the cost per unit of gas.
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document.write( "Write equations as you read \r\n" );
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document.write( "    300E + 140G = 106.20     (1)\r\n" );
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document.write( "    250E + 250G = 112.50     (2)\r\n" );
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document.write( "You need find G.  Use the determinant method (the Cramer's rule)\r\n" );
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document.write( "    G = \"%28300%2A112.50+-+250%2A106.20%29%2F%28300%2A250-250%2A140%29\" = 0.18  dollars.    ANSWER\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved.\r
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\n" ); document.write( "\n" ); document.write( "Do not be scared seeing this long formula filled with numbers.\r
\n" ); document.write( "\n" ); document.write( "You can get the answer in  ONE  CLICK  copying this formula into the  Excel spreadsheet
\n" ); document.write( "or using this convenient online calculator www.desmos.com\r
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\n" ); document.write( "\n" ); document.write( "On the  Determinants' method for solving systems of two linear equations in two unknowns see the lesson \r
\n" ); document.write( "\n" ); document.write( "    - Solution of the linear system of two equations in two unknowns using determinant \r
\n" ); document.write( "\n" ); document.write( "in this site.\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 lesson is the part of this online textbook under the topic  \"Systems of two linear equations in two unknowns\".\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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