Hi there!
a. 
To find the total amount of people that have ENTERED by t = 20, we must take the integral of the appropriate function. 

Evaluate using a calculator:

b. 
To solve, we can find the total amount of people that have entered of the interval and subtract the total amount of people that have left from this value. 
In other terms:

We can evaluate using a calculator (math-9 on T1-84):


c. 
If:

Then:

Evaluate at t = 20:


This means that at t = 20, there is a <u>NET DECREASE</u> of people at the movie theater of around 20.823 (21) people per hour. 
d.
To find the maximum, we must use the first-derivative test. 
Set S(t) - R(t) equal to 0:

Graph the function with a graphing calculator and set the function equal to y = 0:
According to the graph, the graph of the first derivative changes from POSITIVE to NEGATIVE at t ≈ 17.78 hours, so there is a MAXIMUM at this value. 
<u>Thus, at t = 17.78 hours, the amount of people at the movie theater is a MAXIMUM.</u>
 
        
             
        
        
        
Answer: 
monthly cost = 641
Explanation:
Annual mortgage = 0.05×80000
 = 4000
Monthly mortgage = 4000/12= 333
Annual average cost of house = 0.0409×100000 = 4090
Monthly average cost of house = 4090/12 = 341
Monthly cost = 333+ 341 
 = 674
 
        
                    
             
        
        
        
Okay so we have gateway drugs, and over the counter drugs. There are more drugs but I'm afraid I don't have enough space. Gateway drugs are the worst, they are what start people off. say you had a friend that took marijuana and then went up to meth. they started off on marijuana, the gateway drug, they got so used to it that it didn't affect them anymore so they up graded. Drugs are always serious not matter the dose you take. I hope this helped
        
             
        
        
        
<span>The stars change position in the sky through the course of the night just like the sun changes position in the sky through the course of a day, they rise in the east and set in the west. If you were to start watching a star in the east at the beginning of the night and keep observing that same star for hours, you will see the star's position move across the sky and eventually drop below the western horizon. There some stars that don't rise and set through the night though. The stars near the celestial pole move in circles around the pole. There is one star in the sky that doesn't appear to move at all, because it is located in line with the Earth's axis of rotation, or in other words, on the celestial pole. This star is Polaris, or more commonly known as the North Star. The south celestial pole currently lacks a star so there is no southern hemisphere counterpart. In reality, Polaris isn't perfectly on the celestial pole so even it moves in a very small circle too small to be seen with the naked eye.</span>
        
             
        
        
        
The type of relationship they share is a flexible relationship cause they both have or share the same job