﻿ If sum of the coefficients of x7 and x4 in the expansion of  : Kaysons Education

# If Sum Of The Coefficients Of x7 and x4 in The Expansion Of

#### Video lectures

Access over 500+ hours of video lectures 24*7, covering complete syllabus for JEE preparation.

#### Online Support

Practice over 30000+ questions starting from basic level to JEE advance level.

#### Live Doubt Clearing Session

Ask your doubts live everyday Join our live doubt clearing session conducted by our experts.

#### National Mock Tests

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

#### Organized Learning

Proper planning to complete syllabus is the key to get a decent rank in JEE.

#### Test Series/Daily assignments

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

## Question

### Solution

Correct option is

ab = 1

For the coefficient of x7 set 22 – 3r = 7 or r = 5 for the coefficient of x4r= 6.

#### SIMILAR QUESTIONS

Q1

If the fifth term in the expansion of  does not depend upon x, then  equals

Q2

the greatest term in absolute value in the expansion of (a +b)50 is

Q3

Coefficient of the term independent of x in the ex pansion of  is

Q4

Value (s) of x for which the fourth term in the ex pansion of  is 40 is (are)

Q6

If x2r occurs in  then n – 2r must be of the form

Q7

If the coefficient of rth, (r + 1)th and (r  + 2)th terms are in A.P., then n is a root of the equation

Q8

then n must be equal to

Q9

If in the expansion of (21/3 + 3–1/3)n, the ratio of the 7th term from the beginning to the 7th terms from the end is 1: 6, then n is equal to

Q10

Coefficient of x9 in the expansion of