How many times do 15 minutes fit into one hour? 4 times: 4*15=60 mins.
So that means that 4 times per hour 10 flights appear, and in total 4*10=40 planes arrive over one hour!
Answer: 16) 
(17) 
(18) 
(19) 3x - 18
<u>Step-by-step explanation:</u>
Inverse is when you swap the x's and y's and then solve for y
16) Given: y = x²
Swapped: x = y²
17) Given: y = 2x + 4
Swapped: x = 2y + 4
x - 4 = 2y
18) Given: y = (x + 2)²
Swapped: x = (y + 2)²
√x = y + 2
19) Given: 
Swapped: 
3(x - 6) = y
3x - 18 = y
Answer:
r(t) = 15t+500
Step-by-step explanation:
Since the amount of money (r) is a function of the time (t) we will make it the y-value. t is how much time and he gets $15 a minute so we multiply t by 15. 500 is how much he gets paid for doing it. If he showed up and just left, he would still get 500.
<span>The area of the base is x^2> The height is h. Each side of the box has area xh. There are 4 sides of the box so the total surface area of the box is x^2+4xh and that is equal to 1000. Solve that equation for h:
x^2+4xh = 1000 h = (1000-x^2)/4x so the Volume = x^2[(1000-x^2)/4x]
Simplify and get V = 250x-x^3/4
The volume will be a maximum when its first derivative is 0.
V' = 250-3/4x^2
Set to 0 and solve. x=18.26
Now plug into the volume function to find the maximum volume:
V=250(18.26)-(18.26)^3/4
V= 4564.35 - 1522.10 =3042.25</span>
The answer is D. There is a positive correlation between the hours studied and grades earned.
