Step 1 :The given expression is \( \log _{7}\left(4 x^{4}\right)-\log _{7}(11 x) \).
Step 2 :According to the properties of logarithms, the subtraction of two logarithms with the same base can be rewritten as the logarithm of the quotient of their arguments.
Step 3 :So, we can rewrite the expression as: \( \log _{7}\left(\frac{4 x^{4}}{11 x}\right) \).
Step 4 :Simplify the fraction inside the logarithm: \( \log _{7}\left(\frac{4 x^{3}}{11}\right) \).
Step 5 :This is the simplest form of the given expression, so the final answer is \( \boxed{\log _{7}\left(\frac{4 x^{3}}{11}\right)} \).