General term - nCr * (x^2)^(n-r) (3y)^r It is given that 2n - 2r + r = 52n - r = 5n = 4 => r = 3 So the term we have here is 4C3 * (x^2)^1 (3y)^3Coefficient = 4C3 * 3^3 = 4 * 27 = 108