Answer:
The last one, −2.1−(5.9+3.7)
Step-by-step explanation:
−2.1+(−5.9)+(−3.7) = -2.1-5.9-3.7 = -11.7
the only expression that will come out as -11.7 is the last one
Given that the subway stations are 930 m apart, the train have to be accerelated for half the distance and then decerelated for the rest of the distance.
Recall that the distance travelled by an object with an initial velocity, u, for a period of time, t, at an accereration, a, is given by

But, we assume that the train accelerates from rest, thus

The maximum speed is attained at half the center of the distance between subway stations (i.e. at distance = 465 m).
Thus, maximum speed = distance / time = 465 / 23.12 = 20.11 m/s.
3323.5 because if you times the number left by the 15 percent this is the answer.