document.write( "Question 185628: x^2+20=4x \n" ); document.write( "
Algebra.Com's Answer #139229 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "\"x%5E2%2B20=4x\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2%2B20-4x=0\" Subtract 4x from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-4x%2B20=0\" Rearrange the 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=-4\", and \"c=20\"\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-%28-4%29+%2B-+sqrt%28+%28-4%29%5E2-4%281%29%2820%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=-4\", and \"c=20\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+%28-4%29%5E2-4%281%29%2820%29+%29%29%2F%282%281%29%29\" Negate \"-4\" to get \"4\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+16-4%281%29%2820%29+%29%29%2F%282%281%29%29\" Square \"-4\" to get \"16\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+16-80+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%2820%29\" to get \"80\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+-64+%29%29%2F%282%281%29%29\" Subtract \"80\" from \"16\" to get \"-64\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+-64+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+8%2Ai%29%2F%282%29\" Take the square root of \"-64\" to get \"8%2Ai\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B+8%2Ai%29%2F%282%29\" or \"x+=+%284+-+8%2Ai%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284%29%2F%282%29+%2B+%288%2Ai%29%2F%282%29\" or \"x+=++%284%29%2F%282%29+-+%288%2Ai%29%2F%282%29\" Break up the fraction for each case. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+2%2B4%2Ai\" or \"x+=++2-4%2Ai\" Reduce. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+2%2B4%2Ai\" or \"x+=+2-4%2Ai\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+2%2B4%2Ai\" or \"x+=+2-4%2Ai\" \r
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