Chapter 6.3, Problem 19E

(a)

To determine

Two equations representing the traffic entering and leaving intersections $C\text{and}D$.

(b)

To determine

The system of equations using $x_4$ as one parameter.

(c)

To determine

The largest and smallest possible values for the number of cars leaving intersection $A$ on $10th$ Street.

(d)

To determine

The largest and smallest possible values of the parameter $x_1,x_2,x_3$.

(e)

To determine

It could have been discarded any one of the four original equations without changing the solution and the significance about the original problem.