document.write( "Question 409559: Good evening,I am in need of help of a certain topic\"Linear system using substitution\" Can you use these examples to show me step by step?\r
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Algebra.Com's Answer #288257 by Edwin McCravy(20059) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "Look through both equations to find the term that contains\r\n" );
document.write( "a letter that has the smallest coefficient (in absolute value).\r\n" );
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document.write( "That is the term -y in the first equation\r\n" );
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document.write( "Solve it for y.  Add -4x to both sides:\r\n" );
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document.write( "     4x-y=17\r\n" );
document.write( "    -4x     -4x\r\n" );
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document.write( "       -y=17-4x\r\n" );
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document.write( "Solve for y by dividing every term by the\r\n" );
document.write( "coefficient of y which is -1\r\n" );
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document.write( "        y=-17+4x\r\n" );
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document.write( "Next take the other equation, the one you haven't used,\r\n" );
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document.write( "      -9x+8y=2\r\n" );
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document.write( "and replace y by the right side of the previous equation,\r\n" );
document.write( "placed in parentheses like this: (-17+4x)\r\n" );
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document.write( "So \r\n" );
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document.write( "      -9x+8y=2\r\n" );
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document.write( "becomes\r\n" );
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document.write( "      -9x+8(-17+4x)=2\r\n" );
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document.write( "Then you solve that for x\r\n" );
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document.write( "        -9x-136+32x=2\r\n" );
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document.write( "Combine like terms:\r\n" );
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document.write( "           -136+23x=2\r\n" );
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document.write( "Add 136 to both sides:\r\n" );
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document.write( "           -136+23x =  2\r\n" );
document.write( "            136      136\r\n" );
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document.write( "               23x = 138\r\n" );
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document.write( "Divide both sides by 23\r\n" );
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document.write( "                 x = 6\r\n" );
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document.write( "Go back to the equation\r\n" );
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document.write( "           y=-17+4x\r\n" );
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document.write( "and substitute (6) for x\r\n" );
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document.write( "        y=-17+4(6)\r\n" );
document.write( "        y=-17+24\r\n" );
document.write( "        y=7\r\n" );
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document.write( "So the solution is x=6, y=7, sometimes written\r\n" );
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document.write( "(x,y) = (6,7)\r\n" );
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document.write( "Edwin

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