求二(或三)项式展开式的各项系数和、各项绝对值的系数和、奇(或偶)数项系数和,x的整数次幂的各项系数和,以及各项系数的平方和,是二项式一章中学习的难点,也是各种考试考查的重点。本文举例介绍此类题目的解法,供读者参考。 Find the coefficient sums of the two (or three) expansion terms, the coefficient sums of the absolute values, the coefficient sums of the odd (or even) number terms, the coefficient sums of the integer powers of x, and the coefficients The sum of squares is the difficulty in learning in the binomial chapter and is also the focus of various examinations. This article gives an example of the solution to such problems for readers’ reference.