4 Replies
@Apu
Note for OP
+solved @user1 @user2... to close the thread when your doubt is solved. Mention the users who helped you solve the doubt. This will be added to their stats.coeff of x^3 you can get in 3 ways and coeff of x^4 as well. Take constant from the (1+ax+bx^2) and then x^3 from (1-2x)^18 and thn there will be 2 more cases like this and 3 for x^4
(0,3),(1,2),(2,1) for x^3 and (0,4),(1,3),(2,2) for x^4 after getting the coeff's equate them to zero and then you will get linear equations in 2 variables
thank you