同一平面内不相交的直线叫平行线.利用平行线段的几何性质和直观感可以求解方程组的有关问题,培养同学们的创新能力,下面列举两例,供参考.例1 甲国现在的战略核潜艇数是 m 年前乙国核潜艇数的2倍,乙国现在的核潜艇数与m年前甲国的一样多,假设最近 m 年两国核潜艇数的增加量相同,且两国现有核潜艇总数为 The non-intersecting lines in the same plane are called parallel lines. Using the geometric nature and intuitive sense of the parallel line segments can solve the problems of the equation group and cultivate students’ innovative abilities. Here are two examples for reference: Example 1 Current Strategy of the First Country The number of nuclear submarines is twice as many as the number of nuclear submarines of State B in m years ago. The number of nuclear submarines in country B is the same as the number of countries in country m years ago. It is assumed that the increase in the number of nuclear submarines in the two countries in the recent m years is the same, and the total number of existing nuclear submarines in the two countries. for