document.write( "Question 50805: Please can you help me find x\r
\n" ); document.write( "\n" ); document.write( "-7x + 8y + 3y = 10
\n" ); document.write( "28x/4 - 12y = 7 \n" ); document.write( "

Algebra.Com's Answer #33832 by AnlytcPhil(1806) $\"\"$ $\"About$

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Please can you help me find x\r\n" );
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document.write( "-7x + 8y + 3y = 10\r\n" );
document.write( "28x/4 - 12y   = 7\r\n" );
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document.write( "In the first equation, combine like \r\n" );
document.write( "terms 8y + 3y as 11y\r\n" );
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document.write( "-7x + 11y = 10\r\n" );
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document.write( "In the second equation, in the term\r\n" );
document.write( "28x/4 the 4 can be\r\n" );
document.write( "canceled into the 28 like this\r\n" );
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document.write( " 7\r\n" );
document.write( "28x/4\r\n" );
document.write( "    1\r\n" );
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document.write( "to give 7x - 12y = 7\r\n" );
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document.write( "So we now have this system of equations\r\n" );
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document.write( "-7x + 11y = 10\r\n" );
document.write( " 7x - 12y =  7\r\n" );
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document.write( "Now if we add these equations term-by-term\r\n" );
document.write( "vertically, the x's will cancel:\r\n" );
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document.write( "-7x + 11y = 10\r\n" );
document.write( " 7x - 12y =  7\r\n" );
document.write( "--------------\r\n" );
document.write( "       -y = 17\r\n" );
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document.write( "Divide both sides by -1\r\n" );
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document.write( "        y = -17\r\n" );
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document.write( "Substitute -17 for y in\r\n" );
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document.write( "     7x - 12y =  7\r\n" );
document.write( " 7x - 12(-17) = 7 \r\n" );
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document.write( "     7x + 204 = 7\r\n" );
document.write( "           7x = -197\r\n" );
document.write( "            x = -197/7\r\n" );
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document.write( "Edwin

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