if a plane mirror shifts through a distance of 5 cm towards an object and object shifts through 10 cm towards the mirror then find the shift in the position of an image?

In the case of plane mirror the image distance is always equal to the object distance. let the initial position of object from mirror be x. then distance btwn mirror and object is 2x the mirror is shifted towards object by 5cm, and then object is shifted 15cm towards the mirror, total shifting=20cm towards mirror.

as image dis=obj distance

both will shift 20cm towards the mirror.(image as well as object)