Come valuti 9P4 ?
Risposta:
" "^9P_4" "=3024
Spiegazione:
" "^nP_r" "ha la formula
" "^nP_r" "=(n!)/((n-r)!)
so " "^9P_4" "=(9!)/((9-4)!)
so " "^9P_4" "=(9!)/(5!)=(9xx8xx7xx6xxcancel(5!))/cancel((5!)
" "^9P_4" "=(9!)/(5!)=9xx8xx7xx6=3024
" "^9P_4" "=3024
" "^nP_r" "ha la formula
" "^nP_r" "=(n!)/((n-r)!)
so " "^9P_4" "=(9!)/((9-4)!)
so " "^9P_4" "=(9!)/(5!)=(9xx8xx7xx6xxcancel(5!))/cancel((5!)
" "^9P_4" "=(9!)/(5!)=9xx8xx7xx6=3024