If $y=2 u^{2}-u+5$, and $u=1-x^{2}$, find $d y / d x$.

Step 1 ：\(\frac{dy}{du} = \frac{d}{du}(2u^2 - u + 5)\)

Step 2 ：\(\frac{dy}{du} = 4u - 1\)

Step 3 ：\(\frac{du}{dx} = \frac{d}{dx}(1 - x^2)\)

Step 4 ：\(\frac{du}{dx} = -2x\)

Step 5 ：\(\frac{dy}{dx} = \frac{dy}{du} \cdot \frac{du}{dx}\)

Step 6 ：\(\frac{dy}{dx} = (4u - 1) \cdot -2x\)

Step 7 ：\(\frac{dy}{dx} = -8ux + 2x\)

Step 8 ：Substitute \(u = 1 - x^2\) into the equation

Step 9 ：\(\frac{dy}{dx} = -8x(1 - x^2) + 2x\)

Step 10 ：\(\frac{dy}{dx} = -8x + 8x^3 + 2x\)

Step 11 ：\(\frac{dy}{dx} = 8x^3 - 6x\)

Step 12 ：\(\boxed{\frac{dy}{dx} = 8x^3 - 6x}\)