Find the term independent of x in the expansion of (91 + x + 2x3) .

To Find : term independent of x, i.e. coefficient of x0


Formula :


We have a formula,



Therefore, the expansion of is given by,






Now,




Multiplying the second bracket by 91 , x and 2x3



In the first bracket, there will be a 6th term of x0 having coefficient


While in the second and third bracket, the constant term is absent.


Therefore, the coefficient of term independent of x, i.e. constant term in the above expansion




=-91(2)5 (252)


Conclusion : coefficient of term independent of x =-91(2)5 (252)


1