>According to newton laws if something is in uniform motion and equivalent force is equal to zero then its mass cannot change.

Our book says an object stays in state of rest or motion unless compelled by external force. Now if mass is changing and velocity is not changing there will be non-zero equivalent force, but if equivalent force is equal to zero then mass cannot change. I deduced this, so I am asking for confirmation

***I am just a school kid. I just entered physics so please explain kindly and simply.***