The position of the body at time t is given by s = 25/(t + 5). The time interval under consideration is [-4, 0]
The displacement during this interval is (25/(0 + 5) - 25/(-4 + 5)) = 25(1/5 - 1) = -20 m. The average velocity is -20/(4) = -5 m/s
The instantaneous velocity of the body at any moment t is s' = -25/(t + 5)^2. At t = 0, the velocity is -25/25 = -1 m/s and at t = -4, the velocity is -25/1 = -25 m/s
The instantaneous acceleration of the body at any moment t is 50/(t + 5)^3. At t = 0, the acceleration 0.4 m/s^2. At t = -4, the acceleration is 50 m/s^2
The velocity of the body negative throughout the interval, therefore it does not change direction.
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