9
Q:
A) 14 × 13 × 13! | B) 15 × 14 × 14! |
C) 14 × 12 × 12! | D) 15 × 13 × 13! |
Answer: D) 15 × 13 × 13!
Explanation:
Explanation:
15! - 14! - 13!
= (15 × 14 × 13!) - (14 × 13!) - (13!)
= 13! (15 × 14 - 14 - 1)
= 13! (15 × 14 - 15)
= 13! x 15 (14 - 1)
= 15 × 13 × 13!