我们知道|x|=a(a≥0)的意义是:数轴上的点(x)(注本文中符号(x)表示数轴上的数x所对应的点)到原点的距离是非负数a.推广一下,式子|x-y|=a(a≥0)的意义显然是数轴上点(x)到点(y)的距离为非负数a;式子|m+n|=a(a≥0)意义显然是数轴上点(m)到点(-n)的距离为非负数a.利用这一意 We know that | x | = a (a≥0) means that the point on the number axis (x) (Note that the symbol (x) in this paper means the point corresponding to the number x in the number axis). The distance from the origin is nonnegative a. To generalize, the meaning of the formula | xy | = a (a≥0) is obviously that the distance between the point (x) and the point (y) on the axis is nonnegative a; m + n | ) The significance is obviously that the distance between the point (m) and the point (-n) on the axis is non-negative a.