39+5×{10+10:[25×2+1-(x:9)]}=139
39+5*{10+10:[50+1-(x:9)]} = 139
39+5*(10+10:[51-(x:9)]} = 139
5*{10+10:[51-(x:9)]} = 139-39
5*{10+10:[51-(x:9)]} = 100
10+10:[51-(x:9)] = 100:5
10+10:[51-(x:9)] = 20
10:[51-(x:9) = 20-10
10:[51-(x:9)] = 10
51-(x:9) = 10:10
51-(x:9) = 1
x:9 = 51-1
x:9 = 50
x = 50*9
x = 450 km