近年各地中考甚至竞赛中都涉及:已知一次不等式(组)解集(特解)的情况确定其中的字母系数(也称系数)问题和已知方程不等式混合组中参数的确定问题.由于它综合性强:除要用一次不等式(组)的性质和求解方法外.还要用到一次方程(组)的解法等.同时它的灵活性大,蕴含着不少的数学思想? In recent years, the examinations and even competitions in various regions have involved: Knowing the case of a solution (special solution) of an inequality (group) The problem of determining the letter coefficient (also called a coefficient) and the known equation inequality mixed group is determined. Strong comprehensiveness: In addition to the nature and solving method of the inequalities (groups), the solution of one equation (group) is also used. At the same time, it has great flexibility and contains many mathematical ideas.