Answer: There is a certain way he sets up his lead guitar and rhythm guitar tone on the tone switch.
Explanation: You can mess with the tone switches/volume of one of the options (it varies from model to model, I forget for the les paul), of either lead or rhythm, and switch between them for two different sounds. Try messing around with the tone switches and knobs in each setting and see if you can get a similar sound. Sorry if this answer isn't what you were looking for.
Answer:
Absolute value concerns the distance a value is from 0, without regard to the sign of the value. Positive and negative numbers both take a positive absolute value. In this example, the numbers -1.25 and 1.25 are both exactly 1.5 units from zero, so their absolute values are both 1.25.