document.write( "Question 423206: solving linear systems using substitution, what is
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Algebra.Com's Answer #853209 by ikleyn(53420) $\"\"$ $\"About$

You can put this solution on YOUR website!
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\n" ); document.write( "solving linear systems using substitution, what is
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\n" ); document.write( "\n" ); document.write( "        The solution in the post by @mananth is irrelevant, since it is done\r
\n" ); document.write( "\n" ); document.write( "        using the Elimination method, while the request was to use the Substitution method.\r
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\n" ); document.write( "\n" ); document.write( "        I came to solve the problem as it is requested.\r
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document.write( "Your starting equations are\r\n" );
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document.write( "    4x - 7y = 10    (1)\r\n" );
document.write( "    y = x-7         (2)\r\n" );
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document.write( "Using equation (2), substitute y = x-7 in equation (1), replacing 'y' there\r\n" );
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document.write( "    4x - 7(x-7) = 10.\r\n" );
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document.write( "Simplify and find 'x'\r\n" );
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document.write( "    4x - 7x + 49 = 10\r\n" );
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document.write( "    49 - 10 = 7x - 4x\r\n" );
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document.write( "    39 =    3x\r\n" );
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document.write( "     x =     39/3 = 13.\r\n" );
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document.write( "Now from equation (2)  y = x - 7 = 13 - 7 = 6.\r\n" );
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document.write( "ANSWER.  x = 13,  y = 6.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved as requested.\r
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