Can u post a picture so I can better understand the question?
Explanation: more details.
Answer:

Step-by-step explanation:
refers to the permutations of 5 items taken 3 at a time. To evaluate this, we use factorials as follows;

The factorial of an integer n is evaluated as;

Using this concept, the above expression can now be simplified as follows;

Therefore, the permutations of 5 items taken 3 at a time is 60.
The next expression,
refers to the combinations of 6 items taken 4 at a time. The simplification utilizes similar concepts of permutations since we shall be involving factorials;

Therefore, the combinations of 6 items taken 4 at a time is 15.
The final step is to evaluate the product;

Answer:
x = 7.5
Step-by-step explanation:
Since DF bisects ∠CDE then
∠EDF = ∠CDF, hence
8x = 4x + 30 ( subtract 4x from both sides )
4x = 30 ( divide both sides by 4 )
x = 7.5
Answer:
80
Step-by-step explanation: