Question

The coefficient of x^-3 in the expansion of (x-m/x)¹¹ is :

A. -924m⁷

B. -792m⁵

C. -792m⁶

D. -330m⁷

Answer 1

Option : (D)

(x-m/x)¹¹

⇒11-2k = -3 

⇒14-2k = 0 

⇒ k = 7 

For k = 7; coefficient is :

= \(\frac{11!}{7!\times 4!}(-m)^7\)

=- 330m⁷