\(9!-8!-7!.8^2\)
\(=362880-40320-5040.64\)
\(=362880-40320-322560\)
\(=322560-322560\)
\(=0\)
dễ:
9!-8!-7!.8^2=20321280
9!,8!,7! là giai thừa chứ gì.
9!-8!-7!.82
=7!.8.9-7!.8-7!.82
=8.9-8-82
=72-8-64
=0
tk nha
\(9!=362880\)
\(8!=40320\)
\(7!=5040\)
Theo đề ta có:
\(362880-40320-5040.8^2\)
\(=322560-5040.64\)
\(=322560-322560\)
\(=0\)