Notes:
Note that the capacitor size has been chosen for negligible capacitive reactance (XC) at the specific frequency, such that the 10 kΩ DC bias resistors present negligible loading to the coupled AC signal. This is typical for this type of ให้น้ำหนัก circuit.
Aside from giving students an excuse to apply the Superposition Theorem, this question previews a circuit topology that is extremely common in transistor amplifiers.