计算: (1)-an(an+1-an+an-1-2); (2)x2(x-1)+2 发布时间:2017-05-24 17:26 │ 来源:www.tikuol.com 题型:解答题 问题: 计算:(1)-an(an+1-an+an-1-2);(2)x2(x-1)+2x(x2-2x+3).