在数学问题的求解过程中,有时对一些未知量只需设出,而不必求出其值,我们称这种方法为设而不求法.利用设而不求法解某些应用题,往往具有事半功倍之效,现举例说明. In the process of solving mathematics problems, sometimes some unknowns need only be set up, and it is not necessary to find out their values. We call this method as design without seeking the law. The use of design but not solution of certain application problems often has a multiplier effect. The effect is now illustrated.