Please answer with The Network Simplex Method

4. Find the optimal solution for figure below FIGURE 66 75 $15 (100) 1 50 $10 40 $5 3 30 $10 50 $10 60 $8 60 $30 6 5 40 $25 40 $10 30 $5 100 $45 40 $10 50 $30 80 $15 7) (-25) 100 $45 8) (-75)