(1) 由二项式定理得,f=1^5=1(2)同理得,C(5,0)+C(5,1)+C(5,2)+C(5,3)+C(5,4)=2^5-1=31(3)a+c+e=C(5,0)+C(5,2)+C(5,4)=1+10+5=16 b+d=C(5,1)+C(5,3)=5+10=15