To solve the moving point problem, we must first understand the meaning of the problem, understand the whole process of motion and the change of the graph, then draw the graph according to the classification discussion of the motion process, and finally find the equivalent relationship equation for different situations to solve. For the moving point problem based on the number axis, there are often two different solutions because of the characteristics of the number axis itself.

One is to find the equivalent relationship according to the analysis of the relationship between "shape", that is, to solve it by using the equation of the quantitative relationship between each line segment; The other is to find the equivalent relationship from the aspect of "number", that is, to form equations by using the internal relationship between numbers represented by points on the number axis.

Representation of a moving point on the number axis;

It can be solved by addition or subtraction of rational numbers, that is, from the starting point, the moving distance of the moving point is increased and decreased in the positive direction. For example, the number corresponding to point A on the number axis is-1, and point P starts from point A and moves to the right at a speed of 2 unit lengths per second. Let the moving time be t and the number represented by point p be-1+.