This method refers to the method of solving application problems by eliminating unknowns.

When there are two or more unknowns in the problem, it is impossible to find them at the same time. At this time, we must first eliminate some unknowns and reduce them to one, so as to find a solution to the problem.

By eliminating the number of unknowns, the quantitative relationship in the problem can be simplified, so that one unknown can be solved first, and then the required results can be substituted into the original problem, and the method of solving other unknowns step by step is called elimination.