Factorials - Find x if x/10! = 1/8! + 1/9!
Question:
Find x if x/10! = 1/8! + 1/9!
Solution:
x/10! = 1/8! + 1/9!
∴ x/10! = (10 x 9) / [(10 x 9) x 8!] + 10 / 10 x 9!
∴ x/10! = (10 x 9) / 10! + 10 / 10!
∴ x/10! = (10 x 9) + 10 / 10!
∴ x/10! = (90 + 10) / 10!
∴ x/ ̶1̶0̶!̶ = (90 + 10) / ̶1̶0̶!̶
∴ x = (90 + 10)
∴ x = 100
Answer:
x = 100 if x/10! = 1/8! + 1/9!
Video Solution:
