Answer:

Step-by-step explanation:
To answer this problem, we must bear in mind that the express train travels 3 times faster than the freight train.
If we call F the distance that the freight train travels and we call E at the distance that the express train travels, we must have the distance between them after 15 minutes it must be 30 miles.
So

We also know that:
Since the express train travels 3 times faster than the freight train.
So, like both equations, we have to:

Then
miles in the opposite direction.
This is the distance you traveled in 15 minutes.
Therefore, the speed of the express train (
) is the distance traveled between the time it did

Answer:
12 possibilities
Step-by-step explanation:
In the first urn, we have 4 balls, and all of them are different, as they have different labels, so the group of two red balls r1 and r2 is different from the group of red balls r2 and r3.
The same thing occurs in the second urn, as all balls have different labels.
The problem is a combination problem (the group r1 and r2 is the same group r2 and r1).
For the first urn, we have a combination of 4 choose 2:
C(4,2) = 4!/2!*2! = 4*3*2/2*2 = 2*3 = 6 possibilities
For the second urn, we also have a combination of 4 choose 2, so 6 possibilities.
In total we have 6 + 6 = 12 possibilities.
Slope = m
Equation to find slope is:
m = (y2 - y1) / (x2 - x1)
2 points:
(4,-2) 4 = x1 and -2 = y1
(8,5) 8 = x2 and 5 = y2
So...
m = (y2 - y1) / (x2 - x1)
m = (5 - (-2)) / (8 - 4)
m = 7 / 4 or 1.75
Therefore, the slope of the line is 7/4 OR 1.75.