Find the coefficient of `x^7` in the expansion of `(3x^2+ 1/(5x))^11`

Find the coefficient of x^5 in the expansion of (x+3)^9

Find the coefficient of x^7 in the expansion of (2x^2+- 1/x)^20

Find the coefficient of x^(7) in the expansion of (ax^(2) + (1)/(bx))^(11) . (ii) the coefficient of x^(-7) in the expansion of (ax + (1)/(bx^2))^(11) . Also , find the relation between a and b , so that these coefficients are equal .

Find the coefficient of x^(-5) in the expansion of (2x^(2)-(1)/(5x))^(8)

Find the coefficient of x^(7) in the expansion of (2x^(2)-(1)/(x))^(20)

Find the coefficient of x^(7) in the expansion of (2x^(2)-(1)/(x))^(20)

Find the coefficient of x^(6) in the expansion of (3x^(2)-(1)/(3x))^(9)