若n=T r 1 =C 6 r (x) 6-r (- ) r =(-2) r C 6 r , =0,解可得r=4; r=4时,T 5 =(-2) 4
若n=T r 1 =C 6 r (x) 6-r (- ) r =(-2) r C 6 r , =0,解可得r=4; r=4时,T 5 =(-2) 4
发布时间:2025-07-18 08:08:57
若n=T r 1 =C 6 r (x) 6-r (- ) r =(-2) r C 6 r , =0,解可得r=4; r=4时,T 5 =(-2) 4