document.write( "Question 264851: 7x-4y=-3
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Algebra.Com's Answer #854030 by ikleyn(53727) $\"\"$ $\"About$

You can put this solution on YOUR website!
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\n" ); document.write( "7x - 4y = -3
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\n" ); document.write( "\n" ); document.write( " The solution and the answer in the post by @mananth are incorrect.\r
\n" ); document.write( "\n" ); document.write( " See below my correct solution.\r
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document.write( "Your starting equation are\r\n" );
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document.write( "    7x - 4y = -3    (1)\r\n" );
document.write( "    2x + 5y =  8    (2)\r\n" );
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document.write( "Let' solve the system by the Elimination method.\r\n" );
document.write( "For it, multiply equation (1) by 2 (both sides) and multiply equation (2) by 7 (both sides).\r\n" );
document.write( "You will get\r\n" );
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document.write( "    14x -  8y = -6    (3)\r\n" );
document.write( "    14x + 35y = 56    (4)\r\n" );
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document.write( "From equation (4), subtract equation (3).  The terms '14x' will cancel each other, and you will get\r\n" );
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document.write( "          35y - (-8y) = 56 - (-6),\r\n" );
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document.write( "              43y     =     62,\r\n" );
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document.write( "                y     =     62/43.\r\n" );
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document.write( "To find 'x', substitute y = 62/43 in equation (2)\r\n" );
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document.write( "    2x +  = 8,\r\n" );
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document.write( "    2x =  =  = .\r\n" );
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document.write( "     x = .\r\n" );
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document.write( "ANSWER.  x = ,  y = .\r\n" );
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\n" ); document.write( "\n" ); document.write( "At this point the problem is solved completely.\r
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\n" ); document.write( "\n" ); document.write( "There is no need to convert this solution in rational numbers to decimals as @mananth does.\r
\n" ); document.write( "\n" ); document.write( "The meaning of the problem is to get a precise solution in rational numbers,
\n" ); document.write( "and the problem does not ask to convert (to round) them in decimals.\r
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\n" ); document.write( "\n" ); document.write( "Making conversion (rounding), you lose the precision.\r
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\n" ); document.write( "\n" ); document.write( "Had the problem specially request for rounding, it would be justified.\r
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\n" ); document.write( "\n" ); document.write( "Without a special request for rounding, in this problem it is better
\n" ); document.write( "to present a precise solution in rational numbers.\r
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\n" ); document.write( "\n" ); document.write( "I perfectly know/understand WHY @mananth makes rounding here - it is because his computer code, \r
\n" ); document.write( "\n" ); document.write( "which he permanently uses to generate the solution files, is programmed this way.\r
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\n" ); document.write( "\n" ); document.write( "But having incorrect (incorrectly written) computer code is not an argument to teach students in a wrong way.\r
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