document.write( "Question 195715: I hope i picked the right section to put this problem in.\r
\n" ); document.write( "\n" ); document.write( "alright here is the problem, i am totally lost on how to do this:\r
\n" ); document.write( "\n" ); document.write( "(x/x+4) - (2/x-1) = (20/x^2+3x-4)\r
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Algebra.Com's Answer #146759 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"x%2F%28x%2B4%29-2%2F%28x-1%29=20%2F%28x%5E2%2B3x-4%29\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"x%2F%28x%2B4%29-2%2F%28x-1%29=20%2F%28%28x%2B4%29%28x-1%29%29\" Factor. Take note that \"x%3C%3E-4\" or \"x%3C%3E1\" as these values cause a division by zero.\r
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\n" ); document.write( "\n" ); document.write( " Multiply every term on both sides by the LCD \"%28x%2B4%29%28x-1%29\". Doing this will eliminate all of the fractions.\r
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\n" ); document.write( "\n" ); document.write( "\"%28x-1%29%28x%29-%28x%2B4%29%282%29=20\" Cancel out and simplify\r
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\n" ); document.write( "\n" ); document.write( "\"x%28x-1%29-2%28x%2B4%29=20\" Rearrange the terms.\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-x-2x-8=20\" Distribute.\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-x-2x-8-20=0\" Subtract 20 from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-3x-28=0\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "Notice we have a quadratic equation in the form of \"ax%5E2%2Bbx%2Bc\" where \"a=1\", \"b=-3\", and \"c=-28\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for x\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29\" Start with the quadratic formula\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%28-3%29+%2B-+sqrt%28+%28-3%29%5E2-4%281%29%28-28%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=-3\", and \"c=-28\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+sqrt%28+%28-3%29%5E2-4%281%29%28-28%29+%29%29%2F%282%281%29%29\" Negate \"-3\" to get \"3\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+sqrt%28+9-4%281%29%28-28%29+%29%29%2F%282%281%29%29\" Square \"-3\" to get \"9\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+sqrt%28+9--112+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-28%29\" to get \"-112\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+sqrt%28+9%2B112+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%289--112%29\" as \"sqrt%289%2B112%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+sqrt%28+121+%29%29%2F%282%281%29%29\" Add \"9\" to \"112\" to get \"121\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+sqrt%28+121+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+11%29%2F%282%29\" Take the square root of \"121\" to get \"11\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B+11%29%2F%282%29\" or \"x+=+%283+-+11%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2814%29%2F%282%29\" or \"x+=++%28-8%29%2F%282%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+7\" or \"x+=+-4\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the possible answers are \"x+=+7\" or \"x+=+-4\" \r
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\n" ); document.write( "\n" ); document.write( "However, we stated earlier that \"x%3C%3E-4\" or \"x%3C%3E1\" (they cause a division by zero). So we must ignore the possible solution \"x+=+-4\" (it is not in the domain)\r
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\n" ); document.write( "\n" ); document.write( "Answer:\r
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\n" ); document.write( "\n" ); document.write( "So the only solution is \"x+=+7\"
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