Using the knowledge of one-dimensional linear inequality (group), we can solve some specific scheme design problems in economic activities. This kind of test questions is novel and flexible, with a strong flavor of the times, and it is a hot topic in the senior high school entrance examination.

The main types of topics are: 1, purchase scheme design, 2, lease scheme design, 3, shopping scheme design and so on.

This type of question is a complicated process of asking questions, analyzing problems and solving problems, and its solution can be summarized as: obtaining necessary information from practical problems-analyzing and processing relevant information-transforming practical problems into mathematical problems-establishing inequality (group) models-solving this practical problem.

Specifically, this kind of problem generally involves two unknowns. Let one of them represent the other, use the information in the topic to list the inequality groups, solve the set, and take the integer to solve all the schemes. Find the maximum value and minimum value, and get the best scheme through comparison.