1.将多项式x~4-7x~2+1分解为两个整系数多项式的乘积,其次数均不低于一次(5分)。 2.有五卷百科全书由第一卷至第五卷按递增顺序排列。现要求把它们改为按递减顺序排列(即由第五卷到第一卷),每次只准交换相邻两卷的位置,问最少需交换几次(6分)? 3.国际象棋中的王棋(按规定,它可以每次 1. Decompose the polynomial x~4-7x~2+1 into the product of two integer polynomials, the number of which is not less than once (5 points). 2. There are five volumes of encyclopedias from the first volume to the fifth volume in ascending order. It is now required that they should be arranged in descending order (i.e. from volume 5 to volume 1), only to exchange the position of the adjacent two volumes at a time, and ask for a minimum of several exchanges (6 points)? 3. In chess King of chess (as prescribed, it can be every time