Home
Class 12
MATHS
In the expansion of (1+x)^n , 7th and 8t...

In the expansion of `(1+x)^n ,` 7th and 8th terms are equal. Find the value of `(7//x+6)^2` .

Text Solution

Verified by Experts

The correct Answer is:
`n^(2)`

Since the `7^(th)` and `8^(th)` terms are equal , we have
`.^(n)C_(6)x^(6) =.^(n)C_(7)x^(7)`
or `x=(.^(n)C_(6))/(.^(n)C_(7))=(7)/(n-6)`
or `(7/x+6)=n^(2)`
Promotional Banner

Topper's Solved these Questions

  • BINOMIAL THEOREM

    CENGAGE|Exercise Exercise 8.6|10 Videos
  • BINOMIAL THEOREM

    CENGAGE|Exercise Exercise 8.7|9 Videos
  • BINOMIAL THEOREM

    CENGAGE|Exercise Exercise 8.4|13 Videos
  • AREA UNDER CURVES

    CENGAGE|Exercise Question Bank|20 Videos
  • BINOMIAL THEORM

    CENGAGE|Exercise Question Bank|31 Videos

Similar Questions

Explore conceptually related problems

In the expansion of (1+x)^(n),7 th and 8th terms are equal.Find the value of (7/x+6)^(2)

If in the expansion of (a+b)^(n) the coefficient of 4^(th) and 13^(th) term are equal.Find the value of n

If in the expansion of (a-2b)^(n) , the sum of 5^(th) and 6^(th) terms is 0, then th e values of a//b =

In the expansion of (X+y)^(n) , the coefficients of the 17th and the 13th terms equal. Find the numbher of term in the expansion

In the expansion of (1+a)^(34) , if the cofficient of (r-5)^(th) and (2r-1)^(th) terms are equal , then find value of r.

If the 7th terms from the beginning and end in the expansion of ( root(3) 2+1/(root(3)2))^(n) are equal, find the value of n.

If in the expansion of (1 + x)^(20) , the coefficients of r^(th) and (r +4)^(th) terms are equal, then the value of r,is

If the coefficent of (r-5)th and (2r-1)th terms in the expansion of (1+x)^(34) are equal , find the value of r.