document.write( "Question 106811: x+y+z=30000 \r
\n" ); document.write( "\n" ); document.write( ".02x+.03y+.06z=1110 \r
\n" ); document.write( "\n" ); document.write( ".02x+150=.03y : solve for x,y, and z.\r
\n" ); document.write( "\n" ); document.write( "The problem im having with this problem is the \"z\" variable. It is only on 2 of the 3 equations. Ive been trying to solve by using the method of elimination, but I cant seem to isolate the variables. thank you.\r
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Algebra.Com's Answer #77732 by HyperBrain(694)\"\" \"About 
You can put this solution on YOUR website!
Elimination method is perfect for this system!\r
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\n" ); document.write( "\n" ); document.write( "First let's eliminate x! To do that, let's use \"x%2By%2Bz=30000\" and \".02x%2B.03y%2B.06z=1110+\".\r
\n" ); document.write( "\n" ); document.write( "Let's multiply \"x%2By%2Bz=30000\" by 2!\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"2x%2B2y%2B2z=60000\"\r
\n" ); document.write( "\n" ); document.write( "Now, let's multiply \"0.02x%2B0.03y%2B0.06z=1110+\" by 100!\r
\n" ); document.write( "\n" ); document.write( "\"2x%2B3y%2B6z=111000\"\r
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\n" ); document.write( "\n" ); document.write( "It's elimination time!\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Line up the equations\r
\n" ); document.write( "\n" ); document.write( "_____________________________2x+3y+6z=111000
\n" ); document.write( "_____________________________2x+2y+2z=60000\r
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\n" ); document.write( "\n" ); document.write( "If you subtract
\n" ); document.write( "\"2x%2B2y%2B2z=60000\" from \"2x%2B3y%2B6z=111000\",\r
\n" ); document.write( "\n" ); document.write( "you'll get \r
\n" ); document.write( "\n" ); document.write( "\"y%2B4z=51000\"\r
\n" ); document.write( "\n" ); document.write( "Solving \"y%2B4z=51000\".\r
\n" ); document.write( "\n" ); document.write( "\"y=-4z%2B51000\"\r
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\n" ); document.write( "\n" ); document.write( "Now, let's eliminate y! we'll do that by using \"0.02x%2B0.03y%2B0.06z=1110+\" and
\n" ); document.write( "\"0.02x%2B150=0.03y\"\r
\n" ); document.write( "\n" ); document.write( "Solving \"0.02x%2B150=0.03y\",\r
\n" ); document.write( "\n" ); document.write( "\"0.02x-0.03y=-150\"\r
\n" ); document.write( "\n" ); document.write( "Multiplying this by 100,\r
\n" ); document.write( "\n" ); document.write( "\"2x-3y=-15000\"\r
\n" ); document.write( "\n" ); document.write( "Multiplying \".02x%2B.03y%2B.06z=1110+\" by 100,\r
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\n" ); document.write( "\n" ); document.write( "\"2x%2B3y%2B6z=111000\"\r
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\n" ); document.write( "\n" ); document.write( "it's elimination time!\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Line up the equations!\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "______________________________2x+3y+6z=111000
\n" ); document.write( "______________________________2x-3y =-15000\r
\n" ); document.write( "\n" ); document.write( "If you add these, you'll get:\r
\n" ); document.write( "\n" ); document.write( "\"4x%2B6z=96000\"\r
\n" ); document.write( "\n" ); document.write( "Solving this,\r
\n" ); document.write( "\n" ); document.write( "\"4x=-6z%2B96000\"
\n" ); document.write( "\"x=-3z%2F2%2B24000\"\r
\n" ); document.write( "\n" ); document.write( "Substituting \"x=-3z%2F2%2B24000\" and \"y=-4z%2B51000\" to \"2x-3y=-15000\",\r
\n" ); document.write( "\n" ); document.write( "\"2%28-3z%2F2%2B24000%29-3%28-4z%2B51000%29=-15000\"
\n" ); document.write( "\"-3z%2B48000-%28-12z%2B153000%29=-15000\"
\n" ); document.write( "\"-3z%2B48000%2B12z-153000=-15000\"
\n" ); document.write( "\"%28-3z%2B12z%29%2B%2848000-153000%29=-15000\"
\n" ); document.write( "\"9z-105000=-15000\"
\n" ); document.write( "\"9z=-15000%2B105000\"
\n" ); document.write( "\"9z=90000\"
\n" ); document.write( "\"z=10000\"\r
\n" ); document.write( "\n" ); document.write( "Yahoo! we found the value of z at last!\r
\n" ); document.write( "\n" ); document.write( "But wait, there's more!\r
\n" ); document.write( "\n" ); document.write( "Remember that \"x=-3z%2F2%2B24000\". So,\r
\n" ); document.write( "\n" ); document.write( "\"x=-3%2810000%29%2F2%2B24000\"
\n" ); document.write( "\"x=-30000%2F2%2B24000\"
\n" ); document.write( "\"x=-15000%2B24000\"
\n" ); document.write( "\"x=13000\"\r
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\n" ); document.write( "\n" ); document.write( "Also,
\n" ); document.write( "\"y=-4z%2B51000\". So,\r
\n" ); document.write( "\n" ); document.write( "\"y=-4%2810000%29%2B51000\"
\n" ); document.write( "\"y=-40000%2B51000=11000\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "therefore, x=13000, y=11000, and z=10000.\r
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\n" ); document.write( "\n" ); document.write( "Power up,
\n" ); document.write( "HyperBrain!
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