含字母的二元一次方程组的解的讨论,在升学考试,数学竞赛中经常出现,下面通过例题揭示这类问题的解题方法及注意事项. 例1 k为何值时,方程组仅有一组解?无数组解?无解? 解:(2)-(1)消元; The discussion of the solutions of binary equations with letters is often found in the entrance exams and math contests. The following examples illustrate the problem solving methods and precautions of this type of problem. Example 1 When the k value, the equations only have one set Solution? No array solution? No solution? Solution: (2)-(1) elimination;