Answer:
This is the transitive property of equality says that if a = b, and b = c, then a = c
It would be the Associative property of addition i believe <span />
To find f(x) - g(x), simply subtract g(x) from f(x).

If you need to simplify, we can find a common denominator:
0.03 x 40... or its either the other way around like 0.02 x 40 lol
The answer is B: <span>choosing five CDs where not all of them are pop</span>