document.write( "Question 934927: How can i show that nPr = (n-1)P(r) + r*[(n-1)P(r-1) \n" ); document.write( "

Algebra.Com's Answer #568348 by Edwin McCravy(20055) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "xPy = \r\n" );
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document.write( "So we are to prove:\r\n" );
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document.write( "nPr ≟ (n-1)P(r) + r*((n-1)P(r-1)), which becomes:\r\n" );
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document.write( " ≟ \r\n" );
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document.write( " ≟ \r\n" );
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document.write( " ≟ \r\n" );
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document.write( "--------------------------------------------------------------------\r\n" );
document.write( "Proof:\r\n" );
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document.write( "nPr = \r\n" );
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document.write( "Now divide  by long division:\r\n" );
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document.write( "                 1                  \r\n" );
document.write( "           n-r)n+0            \r\n" );
document.write( "               n-r\r\n" );
document.write( "                 r\r\n" );
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document.write( "           The quotient is \r\n" );
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document.write( "nPr = (n-1)P(r) + r\r\n" );
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document.write( "Edwin

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