Hultiply. Assume that all variables represent positive real numbers. \[ (\sqrt{7}+x)^{2} \] \( (\sqrt{7}+x)^{2}=\square \) (Type an exact answer, using radicals as needed. Simplify your answer.)

To simplify \((\sqrt{7}+x)^{2}\), we'll use the formula \((a+b)^{2} = a^{2} + 2ab + b^{2}\). Here, \(a = \sqrt{7}\) and \(b = x\). Calculating each component: 1. \(a^{2} = (\sqrt{7})^{2} = 7\) 2. \(b^{2} = x^{2}\) 3. \(2ab = 2(\sqrt{7})(x) = 2\sqrt{7}x\) Putting it all together: \[ (\sqrt{7}+x)^{2} = 7 + 2\sqrt{7}x + x^{2} \] Thus, the simplified exact answer is: \[ 7 + 2\sqrt{7}x + x^{2} \]