Answer:
The revenue is 
Step-by-step explanation:
From the question we are told that
The rate of change in revenue for Under Armour from 2004 through 2009 is

Now

Integrating both sides to obtain R(t)


=> 
From the question we have that at t = 8 

=> 
So

At t = 9


Answer:
4
Step-by-step explanation:
6-4+2*5=12
12/3
4
Answer:
The open interval of convergence is 1
Step-by-step explanation:
The detailed explanation is given in the attached document.
Assuming you mean y=10x+150 and y=20x+115, you need to use a simultaneous equation, because you have two equations with two unknowns (x and y)
rearrange so
10x-y=-150
20x-y=-115
multiply the top by -1, so that if we add the two lines together, the y will cancel out
-10x+y=150
20x-y=-115
add the two lines together
10x=35
x=3.5
so the time is 3 and a half weeks
then we can sub in x to find y
20x-y=-115
20(3.5)-y=-115
70-y=-115
-y=-185
y=185
so 185 tickets were sold !
you can sub these values into your original equations to check your answer :)