Calculate $\frac{d y}{d x}$. You need not expand your answer.
\[
y=(x+7)\left(x^{2}-7\right)
\]
\[
\frac{d y}{d x}=
\]

Step 1 ：Given the function \(y=(x+7)\left(x^{2}-7\right)\), we are asked to find the derivative of \(y\) with respect to \(x\).

Step 2 ：We will use the product rule for differentiation, which states that the derivative of the product of two functions is the derivative of the first function times the second function plus the first function times the derivative of the second function.

Step 3 ：In this case, the first function is \(x+7\) and the second function is \(x^2 - 7\).

Step 4 ：Applying the product rule, we get \(\frac{d y}{d x} = x^{2} + 2x(x + 7) - 7\).

Step 5 ：So, the derivative of the function \(y\) with respect to \(x\) is \(\boxed{x^{2} + 2x(x + 7) - 7}\).