I believe the next one would be 13.2 because if you add 8.4 to -6.4 it gets 4.8 so you just do the same thing
Answer:

Step-by-step explanation:
Given
P(4,3)
Required
Solve
Using permutation formula;

This implies that





Answer:
0.44444444 or 4/9
Step-by-step explanation:
Since we know the value of
, we can rewrite the equation replacing the variables.

Now solve. While solving, remember the order of operations.
or 