Solve the problem.In an analysis of traffic, a certain city estimates the traffic flow as illustrated in the figure below, where the arrows indicate the flow of traffic. If x1 represents the number of cars traveling from intersection A to intersection B, x2 represents the number of cars traveling from intersection B to intersection C, and so on, we can formulate equations based on the principle that the number of vehicles entering the intersection equals the number leaving it. Formulate an equation for the traffic at each of the four intersections.

Question

A. x1 - x4 = 450
x1 - x2 = 650
x2 - x3 = 1400
x3 - x4 = -1100
B. x1 - x4 = -450
x1 - x2 = -650
x2 - x3 = -1400
x3 - x4 = 1100
C. x1 - x4 = -650
x1 - x2 = -450
x2 - x3 = 1400
x3 - x4 = -1100
D. x1 - x4 = 450
x1 - x2 = 650
x2 - x3 = 1400
x3 - x4 = 1100

Answer 1

Answer: B