用字母表示数是代数学的一个根本特点.它简洁、方便,特别是在描述规律性的问题时,其优越性更加明显.我们在平时的解题中会遇到一些关于常数的问题,由于数值较大或算式本身比较复杂,直接解决较为困难,这时我们可以用字母代替数值,往往能使问题轻松得解.下面举几例说明. The number of alphanumeric characters is a fundamental feature of algebra, which is simple and convenient, especially when it comes to describing the regularity problem, its superiority is more obvious.We will encounter some problems about the constant in the usual problem solving, Larger values ​​or the formula itself is more complicated, directly to solve more difficult, then we can use letters instead of numerical, often make the problem easily understand. Here are a few examples.