If the coefficients of `x^2a n d\ x^3` in the expansion o `(3+a x)^9` are the same, then the value of `a` is `-7/9` b. `-9/7` c. `7/9` d. `9/7`

If the coefficients of x^2a n d\ x^3 in the expansion of (3+a x)^9 are the same, then the value of a is a. -7/9 b. -9/7 c. 7/9 d. 9/7

Find the coefficient of x^(2).y^(7) in the expansion of (x+2y)^(9)

Find the coefficient of x^(2).y^(7) in the expansion of (x+2y)^(9)

If the coefficients of x^7 and x^8 in the expansion of [2 +x/3]^n are equal, then the value of n is : (A) 15 (B) 45 (C) 55 (D) 56

Find the coefficient of x^2 in (7x^3 - (2)/(x^2))^9

If |x^2-7|le 9 then find the values of x

If the sum of coefficients of all even powers in the expansion of (1 + x + x^(2) + ….x^(2n))^(2) is 221. Then the value of n is A. 7 B. 10 C. 11 D. 9

The coefficients of x^7 in the expansion of (1-x^4)(1+x)^9 is (A) 27 (B) -24 (C) 48 (D) -48

If rth term in the expansion of (2x^2-1/x)^(12) is without x then r is equal to a. 7 b. 8 c. 9 d. 10

if 3x-7=9, what is the value of 6x+5?