<---------------------------||----------------------------------------->
A B
50 mph 60 mph
so let's recall that d = rt, distance = rate * time.
both cars start out at the same time, say "t" hours.
after "t" hours car A has covered say "d" miles, since there's a total of 1320, then car B must surely had covered the slack, or 1320 - d.
10 times larger than a thousand. Also one decimal place larger
The answer to your question is negative one over two
This is because the formula for a slope is y2-y1 divided by x2-x1
Hope this helps ;)