If `^0P_5+5^9P_4=^(10)P_r ,` find the value of `rdot`

Explanation

Given,`10_(P_r)=9_(P_5)+5^9P_4`

as we know that

`9_(P_5)=(9!)/((9−5)!)+(5xx9!)/((9−4)!)`

=`(9!)/(4!)+5(9)/(5!)`

=`(5)/(5!)+5/(5!)`



=`(10!)/(5!)`

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