If 1/6! + 1/7! = x/8!, find x

Solution:

It is given that 1/6! + 1/7! = x/8!

Using the definition of factorial,
1/6! + 1/(7 × 6!) = x/(8 × 7 × 6!)
Multiplying both sides by 6!,
1 + 1/7 = x/(8 × 7)
8/7 = x/(8× 7)
So, x = 64

NCERT Solutions Class 11 Maths Chapter 7 Exercise 7.2 Question 4

If 1/6! + 1/7! = x/8!, find x

Summary:

If 1/6! + 1/7! = x/8!, then x = 64