Chapter 1.3, Problem 21E

Network Analysis The figure shows the flow of traffic (in vehicles per hour) through a network of streets.

(a) Solve this system for $x_i,i=1,2,\mathrm{...},5.$

(b) Find the traffic flow when $x_3=0$ and $x_5=100.$

(c) Find the traffic flow when $x_3=x_5=100.$