第1题,
a1C(n,0)+a2C(n,1)+a3C(n,2)+...+a(n+1)C(n,n)
=a1×[C(n,0)×1^n×q^0+C(n,1)×1^(n-1)×q^1+C(n,2)×1^(n-2)×q^2+... +C(n,0)×1^n×q^0]
=a1×(1+q)^n,
第2题,
a1C(n,0)+a2C(n,1)+a3C(n,2)+...+a(n+1)C(n,n)
=a1C(n,0)+(a1+d)C(n,1)+(a1+2d)C(n,2)+...+(a1+nd)C(n,n)
=a1×[C(n,0)+C(n,1)+C(n,2)+...+C(n,n)]+d×[C(n,1)+2C(n,2)+3C(n,3)+...+(n-1)C(n,n-1)+nC(n,n)]
=a1×2^n+d×{[C(n,1)+2C(n,2)+3C(n,3)+...+(n-1)C(n,n-1)+nC(n,n)]+[nC(n,0)+(n-1)C(n,1)+...+3C(n,n-3)+2C(n,n-2)+C(n,n-1)]}÷2
=a1×2^n+(nd/2)×2^n
=(a1+nd/2)×2^n