4. The figure shows the ietersections ef four ose-way strets. As yeu study the figure. notice that 200 cars per hour want to enter intersection \( I_{1} \) from the north on 27 th Avenue.Also, 200 ars per hour want to head east from intersection \( \mathrm{L}_{2} \) on Pallm Drive. The letters \( w, x, y \) and \( z \) stand for the number of cars passing between the intersections.
(a) If the traffic is to loep moving, at each intersection the number ef cars eatering per hour must equal the aumber of cars leaving per hour. Hhe this idea to set up a linear system of equations itrvelving \( w, x, y \) and \( x \)
(b) Use Gaussian ellimination (Echulon form) to solve the system.
(c) If coestruction en 27 th Avenue limits a to 54 cars per hoer, how many cars per hour must pass between the other intersections to keep traffic flowing?
\( |5+4+2| \)
