Given,
The initial velocity of the motorcycle, u=25 m/s
The final velocity fo the motorcycle is X m/s
The time duration is Ys.
The acceleration is defined as the time rate of change of velocity. That is, the acceleration of the motorcycle is equal to the ratio of the cange in velocity to the time duration.
Therefore, the acceleration of the motorcycle is
Thus the acceleration of the motorcycle is (X-25)/Y m/s²