document.write( "Question 747338: Solve by substitution. \r
\n" ); document.write( "\n" ); document.write( "X+3Y=15
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Algebra.Com's Answer #852540 by ikleyn(53066) $\"\"$ $\"About$

You can put this solution on YOUR website!
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\n" ); document.write( "Solve by substitution.
\n" ); document.write( "X+3Y=15
\n" ); document.write( "2x-3y=3
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document.write( "You have two equations\r\n" );
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document.write( "    x + 3y = 15,    (1)\r\n" );
document.write( "   2x - 3y =  3.    (2)\r\n" );
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document.write( "They want you solve it by the substitution method.\r\n" );
document.write( "For it, from equation (1) express  x = 15 - 3y  and substirute it into equation (2), replacing x there\r\n" );
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document.write( "    2*(15-3y) - 3y = 3.\r\n" );
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document.write( "Simplify it and find 'y'\r\n" );
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document.write( "    30 - 6y - 3y = 3,\r\n" );
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document.write( "    30 - 3 = 6y + 3y,\r\n" );
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document.write( "      27   =    9y\r\n" );
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document.write( "       y   =    27/9 = 3.\r\n" );
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document.write( "Now  x = 15 - 3y = 15 - 3*3 = 15*9 = 6.\r\n" );
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document.write( "ANSWER.  x = 6,  y = 9.\r\n" );
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document.write( "You may substitute these values into original equation\r\n" );
document.write( "to make sure that this answer is correct.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved.\r
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\n" ); document.write( "\n" ); document.write( "The answer in the post by @lynnlo is incorrect, so please ingnore it.\r
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