1, this question can't see the following figures clearly, that is, Ax walks to Ay first, and then walks from somewhere to somewhere.

2. The problem is to consider the distance from a point to the origin. * * * There are five points that are the sum of their five points to the origin: = |-4 |+|-3 |+|-1|+1+3 = 12, and the total distance is12.

3. Solution: If the shortest total distance must be between A 1 and A5, set some points at A, and you can get the following formula of total distance: |-4-a |+|-3-a |+|-1-a |+|1-a | |-.

( 1)、 1 & lt； a & lt3 = 3a+ 10 >； 13

(2)、- 1 & lt； A< 1 gets11< a+12 < 13

(3)、-3 & lt； a & lt- 1 gets = 10-a gets 13 & gt； 10-a & gt； 1 1

(4)、-4 & lt； A & lt-3a+4 from-3 and16 >:-3a+4 >; 13

It can be concluded from the above results that they are all greater than 1 1. Considering equality, they are greater than or equal to 1 1, and the shortest distance is 1 1. At this time, a=- 1.

This problem is to investigate the distance between two points on the number axis and the simplification of absolute sign, as well as the operation of removing absolute sign. I don't know if you're satisfied,

Happy life! Learn and progress!