The equation to determine the cutoff frequency of the different filter created by the two 100Ω resistors and the 1μF capacitor is
1 / (2 * pi * R * C) or 1 / (2 * 3.14159 * 100 * 1e-6) = 1592 Hz
This is then divided by 2 since it is shared between the two inputs resulting in 796 Hz
The equation for the common-mode filter is exactly the same, except the value is not divided by two since the filter is not shared between the two inputs.
1 / (2 * 3.14159 * 100 * 0.01e-6) = 159,155 Hz