新教材第二册(上)P59介绍了二元一次不等式表示平面区域的知识,说明了在直线Ax+By+C=0的某一侧选取一个特殊点(x0,y0),从Ax0+By0+C的正负来判断Ax+By+C>0表示直线哪一侧的平面区域的方法.我在学习过程中发现一个更为简捷的判断方法,介绍如下: The new Book 2 (above) P59 introduces the knowledge that the binary inequalities represent the plane region and shows that a special point (x0, y0) is selected on one side of the straight line Ax+By+C=0, from Ax0+By0 The method of determining whether Ax+By+C>0 represents the plane area on which side of the straight line A++By+C>0 is a positive or negative of +C. I found a simpler method of judgment in the learning process, which is described as follows: