Treat the "plus positive X" as "minus negative X". Example: Positive two plus positive two equals positive four. Positive two minus negative two equals positive four.
You get a positive subtracted number. A negative minus a positive number will always give a negative answer. And the answer will be more negative than either of the two numbers.
-2 minus 8 is -10.
2 minus -19 is 21.
Positive minus a negative = positive plus a positive two negatives make a positive 3- (-1) = 3 + 1 = 4 5- (-7) = 12
The answer is always positive, regardless of the size of the two numbers.