Question

Find the 9th term in the expansion of (x/a-3/x^2)^12

Answer 1

Hey there !!!

General term of a binomial expansion of the form (X+Y)ⁿ is 
                                                                                             = nCr(X)^n-r(Y)^r
So 9th term of (x/a-3/x²)¹² 

n=12, r=8,X=x/a,Y=3/x²     
 
 =12C₈(x/a)¹²⁻⁸(3/x²)⁸

 =495*3⁸*x⁴/a⁴x¹⁶

 =3247695/x¹²a⁴

HOPE THIS HELPED YOU !!