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:
D
Step-by-step explanation:
![f(x)=(x-1)(x^2+2)^3\\f'(x)=(x-1)*3(x^2+2)^2*2x+(x^2+2)^3*1\\f'(x)=6x(x-1)(x^2+2)^2+(x^2+2)^3\\f'(x)=(x^2+2)^2[6x^2-6x+x^2+2]\\f'(x)=(x^2+2)^2(7x^2-6x+2)\\D](https://tex.z-dn.net/?f=f%28x%29%3D%28x-1%29%28x%5E2%2B2%29%5E3%5C%5Cf%27%28x%29%3D%28x-1%29%2A3%28x%5E2%2B2%29%5E2%2A2x%2B%28x%5E2%2B2%29%5E3%2A1%5C%5Cf%27%28x%29%3D6x%28x-1%29%28x%5E2%2B2%29%5E2%2B%28x%5E2%2B2%29%5E3%5C%5Cf%27%28x%29%3D%28x%5E2%2B2%29%5E2%5B6x%5E2-6x%2Bx%5E2%2B2%5D%5C%5Cf%27%28x%29%3D%28x%5E2%2B2%29%5E2%287x%5E2-6x%2B2%29%5C%5CD)
Answer:
8 positive integers.
Step-by-step explanation:
One value of n would be 15 because 225 = 15^2.
Other values are 225 * n where 15n <= 1000 and n is a perfect square.
So n = 4 gives us 225* 4 = 900 which is a perfect square and 15*4 = 60.
n = 9 gives us 225 * 9 which is a perfect square and 15*9 = 135.
n = 16 gives us 225*16 and 15*16 = 240 , so OK.
n = 25 gives a perfect square and and 15*25 = 375 - so OK.
n = 36 gives a perfect square and 15*36 = 540 - so OK.
n = 49 gives a perfect square and 15*49 = 735 - so OK.
n = 64 gives a perfect square and 15*64 = 960 - so ok.
n = 81 gives a perfect square and 15 * 81 = 1215 so NOT ok.
Answer:
The awnser is eleven hope this helps a bit
