document.write( "Question 154621: hey, i would greatly appreciate it if you could solve this combinatorics problem for me\r
\n" ); document.write( "\n" ); document.write( "(n+2)!/n! = 56
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Algebra.Com's Answer #113858 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( " Expand \"%28n%2B2%29%21\". Notice how each successive term is going down by 1\r
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\n" ); document.write( "\n" ); document.write( " Expand \"n%21\"\r
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\n" ); document.write( "\n" ); document.write( " Subtract and simplify\r
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\n" ); document.write( "\n" ); document.write( "\"Photobucket Cancel out the common terms\r
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\n" ); document.write( "\n" ); document.write( " Simplify\r
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\n" ); document.write( "\n" ); document.write( "\"%28n%2B2%29%28n%2B1%29=56\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "\"n%5E2%2B3n%2B2=56\" FOIL the left side\r
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\n" ); document.write( "\n" ); document.write( "\"n%5E2%2B3n-54=0\" Subtract 56 from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"%28n%2B9%29%28n-6%29=0\" Factor the left side\r
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\n" ); document.write( "\n" ); document.write( "\"n%2B9=0\" or \"n-6=0\" Set each factor equal to zero\r
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\n" ); document.write( "\n" ); document.write( "\"n=-9\" or \"n=6\" Solve for \"n\"\r
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\n" ); document.write( "\n" ); document.write( "So the possible solutions are \"n=-9\" or \"n=6\". However, you cannot evaluate the factorial of a negative number (well not yet anyway). So the only solution is \"n=6\"\r
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