Answer:
455ways
Step-by-step explanation:
This is expressed as 15 C 3 ( C- combination)
The concept of combination is used when we talk about selection.
Now we are selecting 3 from a sample of 15
15 C 3 = 15! / (15-3)! 3! = 15 ×14×13×12!/12!×3×2
= 5 × 7 × 13 = 455ways
Sorry i dont know this answer
Your answer would be x= -42
Idk im just learning that at school
