=(362880 - 322560 - 5040). 16 =317520.16=5080320 9 != 1.2.3.4.5.6.7.8.9=362880 8!= 1.2.3.4.5.6.7.8=322560 7!=1.2.3.4.5.6.7=5040 Đúng thì cho mình
= 1.2.3...9 - 1.2.3...8 - 7 ! . 16 .
= 8 ! ( 9 - 1) - 7 ! . 16 = 8 !.8 - 7 ! . 16 =7 ! 16 - 7 ! .16 = 0