Chapter 1.3, Problem 24E

Network Analysis Water is flowing through a network of pipes (in thousands of cubic meters per hour), as shown in figure.

(a) Solve this system for the water flow represented by $x_{i}i=1,2,\mathrm{...},7.$

(b) Find the water flow when $x_1=x_2=100.$

(c) Find the water flow when $x_6=x_7=0.$

(d) Find the water flow when $x_5=1000$ and $x_6=0$.