

Bài 1: Tính các tổng sau:
a)S1=Cn0+Cn1+Cn2+.....+Cnn
b)S2=Cn0+Cn2+Cn4+.....
c)S3=Cn1+Cn3+Cn5+.... b)[tex]b)S4=Cn0+2Cn0+22Cn0+...+2kCnk+...+2nCnn
e)S5=Cn0+22Cn2+24Cn4+....[/tex]
a)S1=Cn0+Cn1+Cn2+.....+Cnn
b)S2=Cn0+Cn2+Cn4+.....
c)S3=Cn1+Cn3+Cn5+.... b)[tex]b)S4=Cn0+2Cn0+22Cn0+...+2kCnk+...+2nCnn
e)S5=Cn0+22Cn2+24Cn4+....[/tex]