By air, the distance form city A to city B is 3005 miles less than the distance from city C to city D. If the toal of these two distances is 7815 miles, find distance from city C to city D
let x = distance from city C to City D
so, x - 3005 = distance from city A to city B
add these two distances for the total distance of 7815
(x-3005)+x = 7815
2x -3005 = 7815
2x = 7815 +3005
2x = 10820
x = 10820/2
x = 5410 miles = distance from city C to city D
5410 -3005 = 2405 miles= distance from city A to city B