Solve the Problem $x+w=200+500$ Or $x+w=700$ by Writing an Equation Representing the Traffic Entering and Encountered

Multiple Choice

Solve the problem.
-During rush hours, substantial traffic congestion is encountered at the intersections shown in the figure. The arrows indicate one-way streets. As the figure shows, 500 cars per hour come down P Street to intersection A, and 200 cars per hour come down 5th Street to intersection A. x of these cars leave A on P Street and w cars leave A on 5th Street.
The number of cars entering intersection A must equal the number leaving, so that $x+w=200+500$ or $x+w=700$ . By writing an equation representing the traffic entering and leaving each of the intersections A, B, C, and D, obtain a system of four equations. Solve the system using $\mathrm{w}$ as the parameter.

A) $(200-w, 600+w, 1700-w, w)$
B) $(700-w, w-100,1700-w, w)$
C) $(700-\mathrm{w}, 100+\mathrm{w}, 1700-\mathrm{w}, \mathrm{w})$
D) $(700-\mathrm{w}, 600+\mathrm{w}, 800-\mathrm{w}, \mathrm{w})$