document.write( "Question 200869: a(a+1)-3(a+1)=a+1 \n" ); document.write( "
Algebra.Com's Answer #151109 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"a%28a%2B1%29-3%28a%2B1%29=a%2B1\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"a%5E2%2Ba-3a-3=a%2B1\" Distribute\r
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\n" ); document.write( "\n" ); document.write( "\"a%5E2%2Ba-3a-3-a=1\" Subtract \"a\" from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"a%5E2%2Ba-3a-3-a-1=0\" Subtract 1 from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"a%5E2-3a-4=0\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "Notice that the quadratic \"a%5E2-3a-4\" is in the form of \"Aa%5E2%2BBa%2BC\" where \"A=1\", \"B=-3\", and \"C=-4\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for \"a\":\r
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\n" ); document.write( "\n" ); document.write( "\"a+=+%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( "\"a+=+%28-%28-3%29+%2B-+sqrt%28+%28-3%29%5E2-4%281%29%28-4%29+%29%29%2F%282%281%29%29\" Plug in \"A=1\", \"B=-3\", and \"C=-4\"\r
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\n" ); document.write( "\n" ); document.write( "\"a+=+%283+%2B-+sqrt%28+%28-3%29%5E2-4%281%29%28-4%29+%29%29%2F%282%281%29%29\" Negate \"-3\" to get \"3\". \r
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\n" ); document.write( "\n" ); document.write( "\"a+=+%283+%2B-+sqrt%28+9-4%281%29%28-4%29+%29%29%2F%282%281%29%29\" Square \"-3\" to get \"9\". \r
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\n" ); document.write( "\n" ); document.write( "\"a+=+%283+%2B-+sqrt%28+9--16+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-4%29\" to get \"-16\"\r
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\n" ); document.write( "\n" ); document.write( "\"a+=+%283+%2B-+sqrt%28+9%2B16+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%289--16%29\" as \"sqrt%289%2B16%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"a+=+%283+%2B-+sqrt%28+25+%29%29%2F%282%281%29%29\" Add \"9\" to \"16\" to get \"25\"\r
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\n" ); document.write( "\n" ); document.write( "\"a+=+%283+%2B-+sqrt%28+25+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"a+=+%283+%2B-+5%29%2F%282%29\" Take the square root of \"25\" to get \"5\". \r
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\n" ); document.write( "\n" ); document.write( "\"a+=+%283+%2B+5%29%2F%282%29\" or \"a+=+%283+-+5%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"a+=+%288%29%2F%282%29\" or \"a+=++%28-2%29%2F%282%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"a+=+4\" or \"a+=+-1\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"a+=+4\" or \"a+=+-1\"
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