The figure shows three one-way streets with intersections A, B, and C. Numbers indicate the average traffic flow in vehicles per minute. The variables x, y, and z denote unknown traffic flows that need to be determined for timing of stoplights.

(a) If the number of vehicles per minute entering an intersection must equal the number exiting an intersection, verify that the accompanying system of linear equations describes the traffic flow.

(b) Rewrite the system and solve.

(c) Interpret your solution.

A: x + 5 = y + 7

B: z + 6 = x + 3

C: y + 3 = z + 4

cars/ min 7 cars/min A 9 cars/ min x D z cars/ min B cars/ min 6 cars/min