Question 295619
The given equations are 
                 B=0.20(100,000-T)   ...(1)
and              T=0.40(100,000-B)   
                 T = 400000-0.40B     ...(2)


Put B = 0.20(100,000-T) in (2)
T=400000-(0.20(100,000-T)
T= 400000-20000+0.20T
T-0.20T = 200000
0.8T=200000
T=200000/(0.8)
T=2500000
(1)=>  B= 200000-(0.20)*2500000
B=200000-50000
B=150000