Answer:
-3x + 8
Step-by-step explanation:
The railroad track moves in a straight path from station A to station B and then from station B to station C.
Let the distance from station A to station C be AC and the distance from station B to station C as BC while the distance from station A to station B be AB the following equation holds:
AC = AB + BC
Given the distance from station A to station C is 3x + 4 and from station B to C is 6x-4, Hence:
AC = 3x + 4 and BC = 6x - 4.
Using the line segment addition postulate:
AC = AB + BC
3x + 4 = AB + (6x - 4)
AB = 3x + 4 - (6x - 4)
AB = 3x + 4 - 6x + 4
AB = 3x - 6x + 4 + 4
AB = -3x + 8
