Final answer:
The distance between the two cities can be determined by calculating the total distance traveled by both cars when they meet at a point 3 km from halfway. The equation 20x + 18(3-x) = distance between the two cities can be used to solve for the unknown distance.
Step-by-step explanation:
The distance between the two cities can be determined by calculating the total distance traveled by both cars when they meet at a point 3 km from halfway. Let's call the distance between the first city and the meeting point 'x' km. The distance between the second city and the meeting point will then be '3-x' km. Since the cars are traveling in opposite directions, their combined distance traveled when they meet is equal to the total distance between the two cities. This can be represented by the equation:
20x + 18(3-x) = distance between the two cities
Simplifying the equation, we get:
20x + 54 - 18x = distance between the two cities
2x + 54 = distance between the two cities
To find the value of 'x', we can solve for it:
2x = distance between the two cities - 54
x = (distance between the two cities - 54)/2
Once you have the value of 'x', you can substitute it back into the equation to find the distance between the two cities.