用字母表示数是代数的一个重要特点.它可以把数或数量关系简明地表示出来.如“一个数的a倍(a≠0)等于b,求这个数”,用x表示这个数,可得方程ax=b(a≠0).其中x是未知数,a和b是用字母表示的已知数,a是x的系数,叫做字母系数,b是常数项.这种方程叫做字母系数方程。我们用它来表示一元一次方程的标准形式,但这里的a、b是具体的 The use of letters to represent numbers is an important feature of algebra. It can express a number or quantity relation succinctly. For example, “a number of times a (a ≠ 0) is equal to b, find this number”, and x is used to represent this number. Get the equation ax=b(a≠0). where x is unknown, a and b are known numbers in letters, a is the coefficient of x, called the letter coefficient, and b is the constant term. This equation is called the letter coefficient equation . We use it to represent the standard form of the one-dimensional equation, but here the a and b are specific