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

Let x and y represent the numbers of gallons used by the 40 mpg and 35 mpg cars, respectively.
.. x +y = 40 . . . . . . . . . . .total consumption is 40 gallons
.. 40x +35y = 1525 . . . . total miles driven = 1525
Multiply the first equation by 40 and subtract the second.
.. 40(x +y) -(40x +35y) = 40(40) -(1525)
.. 5y = 75
.. y = 15
.. x = 40 -15 = 25
The 40 mpg car consumed 25 gallons.
The 35 mpg car consumed 15 gallons.
Answer:
It would roll in this direction.

Step-by-step explanation:
It would roll to the direction of maximum decrease, which is the -1 times the direction of maximum increase, which is given by the gradient of the function.
Since

For this case, the gradient of your function would be

And -1 times the gradient of your function would be

Then, at

So it would go towards

The magnitud of that vector is

and to conclude it would roll in this direction.

Answer:

Step-by-step explanation:
Given

Required
Graph the solution

Multiply both sides by 3



<em>See attachment for graph (Assume T is on the x-axis)</em>