Answer:
Part a) The speed is 
Part b) After 4 seconds the trains is 24 ft along the track
Part c) 
Step-by-step explanation:
we have
This is the equation of a line in slope intercept form
where
s(t) is the position of a model train in feet
t is the time in seconds
Part a) How fast is the train moving?
The speed of the train is equal to the slope of the linear equation so
The slope m is equal to
therefore
The speed is
Part b) Where is the train after 4 seconds?
For t=4 sec
substitute the value of t in the equation and solve for s
therefore
After 4 seconds the trains is 24 ft along the track
Part c) When will the train be 29 feet along the track?
For s(t)=29 ft
Substitute the value of s(t) in the equation and solve for t
subtract 14 both sides
Divide by 2.5 both sides
rewrite
Answer #1 is the correct answer
Answer:
3
Step-by-step explanation:
9y-18=3y
9y-3y=18
6y=18
y=18/6
y=3
Answer:
Suppose that you have 50 people that like hip hop and 50 people that like country.
Now, the union of those sets would be 50 + 50 = 100 people, right?
Well, this may be incorrect, because in the 50 people that like hip hop, we may have, for example, 10, that also like country (this means that in the 50 people that like country, we also have 10 that like hip hop).
Then when we are adding 50 + 50 we are counting those 10 people in both groups, and that is why the direct addition may be different than the union of both sets.
In more technical words, the union of two sets is equal to the addition of the elements of both sets minus the elements in the intersection of both sets (in our prior example, the 10 people that like hip hop and country music are the intersection of both sets)
