document.write( "Question 1209430: Solve 2x+y=8 and 3x-2y=5 using substitution method \n" ); document.write( "

Algebra.Com's Answer #848800 by ikleyn(52784) $\"\"$ $\"About$

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\n" ); document.write( "Solve 2x+y=8 and 3x-2y=5 using substitution method
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document.write( "Your starting equations are\r\n" );
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document.write( "    2x +  y = 8    (1)\r\n" );
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document.write( "    3x - 2y = 5.   (2)\r\n" );
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document.write( "From equation (1), express y = 8 - 2x  and substitute it into equation (2)\r\n" );
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document.write( "    3x - 2(8-2x) = 5.\r\n" );
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document.write( "You have now one single equation for one unknown x.\r\n" );
document.write( "Simplify and find x\r\n" );
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document.write( "    3x - 16 + 4x = 5,\r\n" );
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document.write( "    3x + 4x = 5 + 16\r\n" );
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document.write( "       7x   =   21\r\n" );
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document.write( "        x   =   21/7 = 3.\r\n" );
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document.write( "So, x is just found, x= 3.\r\n" );
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document.write( "Now substitute x = 3 in the first equation to find y\r\n" );
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document.write( "    2*3 + y = 8,\r\n" );
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document.write( "    y = 8 - 2*3 = 8 - 6 = 2.\r\n" );
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document.write( "ANSWER.  The solution is this pair  (x,y) = (3,2).\r\n" );
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document.write( "CHECK.  Substitute these values x and y into equations to make sure\r\n" );
document.write( "        that left sides are equal to their right sides.\r\n" );
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