设x1,x2,...,xn>0,(1)若1,x1,x2,...,xn,2成等差数列,则x1+x2+...+xn=____;

问题描述:

设x1,x2,...,xn>0,(1)若1,x1,x2,...,xn,2成等差数列,则x1+x2+...+xn=____;
(2)若1,x1,x2,...,xn,2成等比数列,则x1*x2*...*xn=_____.

接管时填数字还是表达式?