Distance = speed x time
Distance travelled by car A when car B started = 60 x 2 = 120 miles
Number of miles remaining at the time car B started = 400 - 120 = 280 miles.
At time of their meeting both cars has travelled a combined distance of 280 miles and has spent the same time.
Let t be the time they travelled together before they meet, then the sum of the distance travelled by car A and car B is 280miles.
60t + 80t = 280
140t = 280
t = 280/140 = 2 hours
After 2 hours car A has travelled a further 60 x 2 = 120 miles and car B has travelled 80 x 2 = 160 miles.
Total distance travelled be car A is 120 + 120 = 240 miles
Midpoint of the journey = 400/2 = 200 miles
Therefre, at the time they met, the were 40 miles from the midpoint and they are close to San Francisco.
The first (and most typical) way to find distance of two points is by using the distance formula.

One alternative is the Manhattan metric, also called the taxicab metric. This option is much more complicated, and rarely used in high school math. d(x,y)=∑i|xi-yi|
The y-intercept will be where it crosses the y-axis. The y-axis is the line that goes up and down also know a vertically.