A stuntman jumping off a 20-m-high building is modeled by the equation h = 20 – 5t2, where t is the time in seconds. A high-speed camera is ready to film him between 15 m and 10 m above the ground. For which interval of time should the camera film him?
Answer:

Step-by-step explanation:
Given:
A stuntman jumping off a 20-m-high building is modeled by the equation
-----------(1)
A high-speed camera is ready to making film between 15 m and 10 m above the ground
when the stuntman is 15m above the ground.
height
Put height value in equation 1





We know that the time is always positive, therefore 
when the stuntman is 10m above the ground.
height
Put height value in equation 1







Therefore ,time interval of camera film him is 
Answer:
Step-by-step explanation:
If an exponential function is in the form of y = a(b)ˣ,
a = Initial quantity
b = Growth factor
x = Duration
Condition for exponential growth → b > 1
Condition for exponential decay → 0 < b < 1
Now we ca apply this condition in the given functions,
1). 
Here, (1 + 0.45) = 1.45 > 1
Therefore, It's an exponential growth.
2). 
Here, (0.85) is between 0 and 1,
Therefore, it's an exponential decay.
3). y = (1 - 0.03)ˣ + 4
Here, (1 - 0.03) = 0.97
And 0 < 0.97 < 1
Therefore, It's an exponential decay.
4). y = 0.5(1.2)ˣ + 2
Here, 1.2 > 1
Therefore, it's an exponential growth.
<span> <span>two numbers are related in this way:
the number 1 is subtracted from the first number, the difference is squared, then doubled;the result is equal to the second number. the number 1 is added to the first number, and the sum is squared;the result is equal to 4 minus the second number. determine the numbers. </span></span>
Answer:
The labor fee is $14.25, each quart of oil costs $2.25.
Step-by-step explanation:
Let $x be thee price of each quart of oil and $y be a flat fee for labor.
1. If the oil change for one car required 5 quarts of oil, then these 5 quarts cost $5x and together with a flat fee for labor it cost $25.50. Thus,
5x+y=25.50.
2. If the oil change for another car required 7 quarts of oil, then these 7 quarts cost $7x and together with a flat fee for labor it cost $30.00. Thus,
7x+y=30.00.
3. Subtract from the second equation the first one, then

Substitute it into the first equation:

The labor fee is $14.25, each quart of oil costs $2.25.
I got the answer isa D mate