[(1+x)^(21)+(1+x)^(22)+.........+(1+x)^(30)(1)/(4)],[[" (A) "^(51)C_(5)," (B) "^(9)C_(5)]],[" 100"]

The coefficient x^(5) in the expansion of (1+x)^(21)+(1+x)^(22)++(1+x)^(30) is a.51C_(5) b.^(9)C_(5) c.^(31)C_(6)-^(21)C_(6) d.^(30)C_(5)+^(20)C_(5)

If coefficient of x^(21) in the expansion of (1 + x)^(21) + (1 + x)^(22) + ... + (1 + x)^(30) is ""^(31)C_(r) , where r ge 20 , then r= ___

Solve: (x)/(30)-(1)/(33)=(x)/(11)-(7)/(22)

The coefficient x^5 in the expansion of (1+x)^(21)+(1+x)^(22)++(1+x)^(30) is a. "^51 C_5 b. "^9C_5 c. "^31 C_6 -"^(21)C_6 d. "^30 C_5 + "^(20)C_5

The coefficient x^5 in the expansion of (1+x)^(21)+(1+x)^(22)++(1+x)^(30) is a. "^51 C_5 b. "^9C_5 c. "^31 C_6 -"^(21)C_6 d. "^30 C_5 + "^(20)C_5

The coefficient x^5 in the expansion of (1+x)^(21)+(1+x)^(22)++(1+x)^(30) is a. "^51 C_5 b. "^9C_5 c. "^31 C_6 -"^(21)C_6 d. "^30 C_5 + "^(20)C_5

(1)/(sqrt(21+4x-x^(2)))

Coefficient of x^5 in ( 1+ x)^21 + (1 + x)^22 + …….+ (1 + x)^30 is

Coefficient of x^5 in ( 1+ x)^21 + (1 + x)^22 + …….+ (1 + x)^30 is

int_(0)^(1)x(1-x)^(4)dx=(1)/(30)