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

To multiply \( (\sqrt{7}+x)^{2} \), you can use the formula for squaring a binomial, which is \( (a+b)^{2} = a^{2} + 2ab + b^{2} \). Here, \( a = \sqrt{7} \) and \( b = x \). So you calculate: 1. \( a^{2} = (\sqrt{7})^{2} = 7 \) 2. \( 2ab = 2(\sqrt{7})(x) = 2\sqrt{7}x \) 3. \( b^{2} = x^{2} \) Putting it all together: \[ (\sqrt{7}+x)^{2} = 7 + 2\sqrt{7}x + x^{2} \] Thus, the answer is: \[ 7 + 2\sqrt{7}x + x^{2} \]