Answer:
- 3 hours
- 1 hour 45 minutes
- 300 miles
Step-by-step explanation:
1. The trains are moving toward each other at a total speed of 50 +20 = 70 miles per hour. Together, they cover the 210 mile distance in ...
time = distance/speed
time = 210 mi/(70 mi/h) = 3 h
The trains collide after 3 hours.
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2. The fly is closing with the freight train at a speed of 100 +20 = 120 miles per hour. Together, the fly and the train cover the initial 210 mile distance in ...
(210 mi)/(120 mi/h) = 7/4 h = 1 hour 45 minutes
The fly first meets the oncoming freight train after 1 h 45 min.
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3. The fly is flying for all three hours before the trains collide, so, at 100 miles per hour, will fly 300 miles.
Answer:
Step-by-step explanation:
It can be found by integral.
First let's find the intersection points.
Only intersection point is x = 2.
And it is asked to find the area in the interval (2, 4).
We will use integration by parts.
16+16+16+9+9=32+16+9+9=48+9+9=57+9=66
The answer is 66
Answer:
(2x-9)(2x+9)
Step-by-step explanation:
This is a difference of squares because it can be written as (2x)^2-9^2
The formula for factoring a difference of squares is a^2-b^2=(a-b)(a+b)
So replace a with 2x and b with 9 giving us
4x^2-81=(2x-9)(2x+9)
Add all of the hours together than divide by 5 should get 40
