The task is to launch a graphic item from a random position along the X coordinate

There is Random from -1 to 1, as well as an incoming signal, at activation of which Hold fixes the value of Random. In parallel, there is an incoming signal 2, which is transformed from 1 to -1. Then these two signals go to Copy, which converts the values.

I’m not entirely happy with the output of Copy. The graphical content reacts well (quickly changes its X position) if the Hold values are above 0.5 or below -0.5. However, if the values are less than 0.5 or greater than -0.5, the graphic item moves noticeably slower.

Can you tell me what mathematical operation should be performed?

in your usage case the Copy CHOP does the same as a Math CHOP multiplying the two CHOPs together.
The speed difference in movement comes from the fact that the trigger’s decay always has the same length not matter the distance and hence traversing a shorter distance (for example -0.3 to 0.3) takes the same time as traversing a longer distance (for example 1 to -1).
To get a constant speed you will have to set the decay parameter of the trigger to some function of the distance traveled - in the most simplest and linear approach, the decay length should be equal the absolute value held in the Hold CHOP.
You can calculate the absolute value with a Math CHOP’s “Channel Pre OP” parameter set to Positive