等差等比数列两个性质及应用柴发林，刘春艳我们知道，等差数列和等比数列是两种最基本、最常见的数列。根据等差数列和等比数列的定义及通项公式可推出以下两个性质，在解决有关问题时，运用这些性质，能使解答简洁、明快。性质１：在等差（比）数列中，项数和相等的两项... Two properties of equal-difference series and their applications. Chai Fa-lin, Liu Chun-yan We know that equal-difference sequences and geometric sequences are the two most basic and common sequences. According to the definition of the arithmetic sequence and geometric sequence and the general formula, the following two properties can be introduced. When these problems are solved, the use of these properties can make the solution concise and clear. Nature 1: In the arithmetic difference (number) series, the number of items and the two equal items...