Ideal Machine:
If a machine has no friction, it shall have no power loss. It shall have 100% efficiency. Thus, output of machine will be equal to the input into the machine.
Input of machine = Output of machine
P × y = W × x
Or,
W / P = y/x
Or, MA = VR
An actual machine cannot be an ideal machine because it shall have friction and there shall be some power loss because of friction.