document.write( "Question 151298: Could you please help me solve the system of equations?
\n" ); document.write( "3x+3y+z=5
\n" ); document.write( "x-3y+2z=-13
\n" ); document.write( "8x-2y+3z=-8
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Algebra.Com's Answer #111200 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"system%283x%2B3y%2Bz=5%2Cx-3y%2B2z=-13%2C8x-2y%2B3z=-8%29\"\r
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\n" ); document.write( "\n" ); document.write( "Add equations 1 and 2. Let's call the result equation 4:\r
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\n" ); document.write( "\n" ); document.write( "\"3x%2B3y%2Bz=5\"
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\n" ); document.write( "\"4x%2B0y%2B3z=-8\" \r
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\n" ); document.write( "\n" ); document.write( "Equation 4: \"4x%2B3z=-8\"\r
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\n" ); document.write( "\n" ); document.write( "\"2%283x%2B3y%2Bz%29=2%285%29\" Multiply both sides of equation 1 by 2\r
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\n" ); document.write( "\n" ); document.write( "\"6x%2B6y%2B2z=10\" Multiply. Let's call this equation 5\r
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\n" ); document.write( "\n" ); document.write( "\"3%288x-2y%2B3z%29=3%28-8%29\" Multiply both sides of equation 3 by 3\r
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\n" ); document.write( "\n" ); document.write( "\"24x-6y%2B9z=-24\" Multiply. Let's call this equation 6\r
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\n" ); document.write( "\n" ); document.write( "Now add equations 5 and 6. Let's call the result equation 7:\r
\n" ); document.write( "\n" ); document.write( "\"6x%2B6y%2B2z=10\"
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\n" ); document.write( "\"30x%2B0y%2B11z=-14\"\r
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\n" ); document.write( "\n" ); document.write( "Equation 7: \"30x%2B11z=-14\"\r
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\n" ); document.write( "\n" ); document.write( "So we now have the two equations equation 4 and equation 7:\r
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\n" ); document.write( "\n" ); document.write( "equation 4: \"4x%2B3z=-8\"
\n" ); document.write( "equation 7: \"30x%2B11z=-14\"\r
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\n" ); document.write( "\n" ); document.write( "Start with the given system of equations:\r
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\n" ); document.write( "\n" ); document.write( "\"system%284x%2B3z=-8%2C30x%2B11z=-14%29\"\r
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\n" ); document.write( "\n" ); document.write( "Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to solve for z.\r
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\n" ); document.write( "\n" ); document.write( "So let's isolate z in the first equation\r
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\n" ); document.write( "\n" ); document.write( "\"4x%2B3z=-8\" Start with the first equation\r
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\n" ); document.write( "\n" ); document.write( "\"3z=-8-4x\" Subtract \"4x\" from both sides\r
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\n" ); document.write( "\n" ); document.write( "\"3z=-4x-8\" Rearrange the equation\r
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\n" ); document.write( "\n" ); document.write( "\"z=%28-4x-8%29%2F%283%29\" Divide both sides by \"3\"\r
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\n" ); document.write( "\n" ); document.write( "\"z=%28%28-4%29%2F%283%29%29x%2B%28-8%29%2F%283%29\" Break up the fraction\r
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\n" ); document.write( "\n" ); document.write( "\"z=%28-4%2F3%29x-8%2F3\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "Since \"z=%28-4%2F3%29x-8%2F3\", we can now replace each \"z\" in the second equation with \"%28-4%2F3%29x-8%2F3\" to solve for \"x\"\r
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\n" ); document.write( "\n" ); document.write( "\"30x%2B11highlight%28%28%28-4%2F3%29x-8%2F3%29%29=-14\" Plug in \"z=%28-4%2F3%29x-8%2F3\" into the first equation. In other words, replace each \"z\" with \"%28-4%2F3%29x-8%2F3\". Notice we've eliminated the \"z\" variables. So we now have a simple equation with one unknown.\r
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\n" ); document.write( "\n" ); document.write( "\"30x%2B%2811%29%28-4%2F3%29x%2B%2811%29%28-8%2F3%29=-14\" Distribute \"11\" to \"%28-4%2F3%29x-8%2F3\"\r
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\n" ); document.write( "\n" ); document.write( "\"30x-%2844%2F3%29x-88%2F3=-14\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"%283%29%2830x-%2844%2F3%29x-88%2F3%29=%283%29%28-14%29\" Multiply both sides by the LCM of 3. This will eliminate the fractions (note: if you need help with finding the LCM, check out this solver)\r
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\n" ); document.write( "\n" ); document.write( "\"90x-44x-88=-42\" Distribute and multiply the LCM to each side\r
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\n" ); document.write( "\n" ); document.write( "\"46x-88=-42\" Combine like terms on the left side\r
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\n" ); document.write( "\n" ); document.write( "\"46x=-42%2B88\"Add 88 to both sides\r
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\n" ); document.write( "\n" ); document.write( "\"46x=46\" Combine like terms on the right side\r
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\n" ); document.write( "\n" ); document.write( "\"x=%2846%29%2F%2846%29\" Divide both sides by 46 to isolate x\r
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\n" ); document.write( "\n" ); document.write( "\"x=1\" Divide\r
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\n" ); document.write( "\n" ); document.write( "So the first part of our answer is: \"x=1\"\r
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\n" ); document.write( "\n" ); document.write( "Since we know that \"x=1\" we can plug it into the equation \"z=%28-4%2F3%29x-8%2F3\" (remember we previously solved for \"z\" in the first equation).\r
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\n" ); document.write( "\n" ); document.write( "\"z=%28-4%2F3%29x-8%2F3\" Start with the equation where \"z\" was previously isolated.\r
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\n" ); document.write( "\n" ); document.write( "\"z=%28-4%2F3%29%281%29-8%2F3\" Plug in \"x=1\"\r
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\n" ); document.write( "\n" ); document.write( "\"z=-4%2F3-8%2F3\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"z=-4\" Combine like terms and reduce. (note: if you need help with fractions, check out this solver)\r
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\n" ); document.write( "\n" ); document.write( "So the third part of our answer is: \"z=-4\"\r
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\n" ); document.write( "\n" ); document.write( "\"3x%2B3y%2Bz=5\" Go back to the first equation \r
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\n" ); document.write( "\n" ); document.write( "\"3%281%29%2B3y%2B%28-4%29=5\" Plug in \"x=1\" and \"z=-4\"\r
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\n" ); document.write( "\n" ); document.write( "\"3%2B3y-4=5\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"3y-1=5\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"3y=5%2B1\" Add \"1\" to both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"3y=6\" Combine like terms on the right side.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%286%29%2F%283%29\" Divide both sides by \"3\" to isolate \"y\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=2\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "So the second part of the answer is \"y=2\" \r
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\n" ); document.write( "\n" ); document.write( "-----------------Summary------------------------------\r
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\n" ); document.write( "\n" ); document.write( "So our answers are:\r
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\n" ); document.write( "\n" ); document.write( "\"x=1\", \"y=2\", and \"z=-4\"\r
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\n" ); document.write( "\n" ); document.write( "They form the point (1,2,-4)\r
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