Explanation: \(\frac{x+7}{7x}-\frac{1}{x} = \frac{x+7-7}{7x} = \frac{x}{7x} = \frac{1}{7}\) (The calculation provided in the source is incorrect, the correct calculation leads to 1/7 which is not an option given, so based on the provided options/solution the answer is 5/none of these, as the provided work is not for any option). \(\frac{x+7}{7x}-\frac{1}{x} = \frac{x^2+7x}{7x^2-1}\) (This calculation is for a different expression, so it's not a correct explanation).
