document.write( "Question 1101918: Solve by elimination addition method 12x+5y=2, -2x+3y=15 \n" ); document.write( "

Algebra.Com's Answer #716544 by ikleyn(52781) $\"\"$ $\"About$

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document.write( " 12x + 5y =  2,     (1)\r\n" );
document.write( " -2x + 3y = 15.     (2)\r\n" );
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document.write( "Multiply eq(2) by 6 (both sides). The modified system is\r\n" );
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document.write( " 12x + 5y =   2,    (3)\r\n" );
document.write( "-12x + 18y = 90.    (4)\r\n" );
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document.write( "Now add equations (3) and (4). You will get\r\n" );
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document.write( "5y + 18y = 2 + 92  ====>  23y = 94  ====>  y =  = 4.\r\n" );
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document.write( "Then from eq(2) -2x = 15 - 3y = 15 - 3*4 = 3  ====>  x =  = -3/2.\r\n" );
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document.write( "Answer.  x = -3/2,  y = 4.\r\n" );
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