1. The problem statement, all variables and given/known data Consider the network of streets with intersections a,b,c,d and e below. The arrows indicate the direction of traffic flow along the oneway streets, and the numbers refer to the exact number of cars observed to enter or leave a,b,c,d and e during one minute. Each xi denotes the unknown number of cars which passed along the indicated streets during the same period. See Attached Image Linear System: x1+x6-x5=55 x5-x4=35 x6+x3-x4=60 x3-x2=40 x1-x2=70 Reduced row-echelon form 1 0 0 0 -1 1 | 55 0 1 0 0 -1 1 |-15 0 0 1 0 -1 1 |25 0 0 0 1 -1 0 |-35 0 0 0 0 0 0 |0 s t General Solution: x1=55+s-t x2=-15+s-t x3=25+s-t x4=-35-s x5=s x6=t The question is: if ED were closed due to roadwork, find the minimum flow along AC, using your results in the genral solution. Note: x2 = ED therefor x2=0, and AC is x6 2. Relevant equations 3. The attempt at a solution I know x2=0 and no idea what to do with S and T... what I did is set x2=0 so -15+s-t=0 so S=t+15 And sub it into the general solution you get: x1=70 x2=0 x3=40 x4=-20+t x5=15+t x6=t so x4≥0 when t≥20 x6≥0 when t≥0 So minflow is 0?