If \(\displaystyle y = \frac{(\sqrt{x} + 1)(x^2 - \sqrt{x})}{x\sqrt{x} + x + \sqrt{x}} + \frac{1}{15}\,(3\cos^2 x - 5)\cos^3 x \), then \( 96\,y'\!\left(\dfrac{\pi}{6}\right) \) is equal to ________.