Converting minimum forms of boolean function?

Question

Discrete Math

The factorial transformation effect associated with the change in the price
of the scheme ΔS _Q due to the removal of m letters from k terms of the MNF can be estimated by the expression where p is the number of terms in which, after the removal of m letters, one letter remains (p ≤ k); Δ=1, if removal is performed from all MNF terms, or Δ=2, if not from all. tell me how S _Q is calculated for each transformation? tell me what is meant by term in this case? and what is under the removal of m letters?