Final answer:
The coach can select 4 out of 9 players in 126 different ways, calculated using the combination formula C(n, r) = n! / (r! * (n - r)!).
Step-by-step explanation:
To determine in how many ways the youth soccer coach can choose 4 out of his 9 players to go into a game, we can use the concept of combinations because the order in which the players are chosen does not matter. The number of combinations of n items taken r at a time is given by the formula:
C(n, r) = n! / (r! * (n - r)!)
Where:
- n is the total number of items.
- r is the number of items to choose.
- ! denotes factorial, the product of all positive integers up to that number.
For this scenario, n = 9 (total players) and r = 4 (players to choose), so the equation becomes:
C(9, 4) = 9! / (4! * (9 - 4)!) = 9! / (4! * 5!) = (9*8*7*6) / (4*3*2*1) = 126
Therefore, the coach can choose the players in 126 different ways.