The answer would just be 50/1 or just 50
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:
a. square root of 5
b. square root of 13
c. 9
d. 13
Step-by-step explanation:
In the first series, the summation applies to the whole (2n+3) inside
the parentheses, so the 3 gets summed up 5 times.
But in the second one, the summation only applies to the 2n , so
the 3 is only added after the summation is finished.
The difference between five 3s the first time and one 3 the second time
is your 12 .
( 1 ,2) is in first quadrant
(-1,2) is in second
(-1,-2) is in the third
( 1, -2) is in 4th quadrant