If its mass is 3.55*105 kg and the net braking force is 4.05*105 n, what is the airplane's acceleration? mastering physics

This problem illustrate an airplane which is decelerating, since it tells us about a braking force, this type of acceleration is opposite in direction or simply a "deceleration" of the aircraft. The given are mass m=3.55 x 10⁵ Kg. The net braking Force f=-4.05 x 10⁵ N or Newton. The formula for the force is equivalent to F=ma. therefore a=f/m or force divided by the mass. This braking force is acting in opposite direction therefore having a negative sign. The answer will be negative in sign reminding us that it is a form of "deceleration". The unit should be in m/s².