eazzy

coefficient of x⁹⁹:

=-1-2-3-4-5....-100
=-(1+2+3+...+100)
=-5050

(For x⁹⁹ we have to multiply 99 brackets with the constant part of 100th bracket.

So multiplying -1 with x of all other brackets we get -x⁹⁹
multiplying -2 with x of all other brackets we get -2x⁹⁹
.
.
.
multiplying -100 with x of all other brackets we get -100x⁹⁹

thank u ...