Answer:
The first 3 terms in the expansion of  , in ascending power of x are,
 , in ascending power of x are,

coefficient of  in the expansion of
 in the expansion of  = (240 - 192) = 48
 = (240 - 192) = 48
Step-by-step explanation:

= 
=  + terms involving higher powers of x
 + terms involving higher powers of x
=  + terms involving higher powers of x
 + terms involving higher powers of x
so, the first 3 terms in the expansion of  , in ascending power of x are,
 , in ascending power of x are,

Again,

= 
Now, by inspection,
the term  comes from k =5 and k = 6
 comes from k =5 and k = 6
for k = 5, the coefficient of   is ,
  is ,  = -192
 = -192
for k = 6 , the coefficient of  is,
 is,  = 240
 = 240 
so,   coefficient of  in the final expression = (240 - 192) = 48
 in the final expression = (240 - 192) = 48