Some radio-nuclides decay by capturing one of their own atomic electrons, K- shell electrons, say. An example

Question:

Some radio-nuclides decay by capturing one of their own atomic electrons, K- shell electrons, say. An example is below. Show that the disintegration energy Q for this process is given by, where mV and mTi, arte the atomic masses of 49V and 49Ti, respectively, and EK is the binding energy of the vanadium K-shell electron.