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 
Sample response: <span>Yes, the fan will provide enough airflow. The volume of the ranger station is 720 cubic feet. The ranger station requires a 720 CFM fan. 1,500 CFM is greater than 720 CFM, so it will be enough airflow.</span>
Answer:
$(55-3m) is the amount of money she has left
Step-by-step explanation:
In this question, we are asked to give an expression to represent how much money was left after Sarah had bought some certain stuffs at some prices using the money she received at her birthday.
Firstly, we identify that the total amount of money she has to spend is $55.
Now let’s project her total spendings. She bought 3 shirts with each shirt costing $m.
The total amount spent on the shirts is thus; 3 * $m = $3m
The amount of money she has left is the difference.
Mathematically, this is equal to $55 - $3m
Answer:
B = (7, 2)
Step-by-step explanation:
B = 2M -A
B = 2(3, 4) -(-1, 6) = (2·3-(-1), 2·4-6)
B = (7, 2)
_____
The expression for the other end point, B, comes from the equation for the midpoint.
M = (A +B)/2
2M = A + B . . . . . multiply by 2
2M -A = B . . . . . . subtract A to get an expression for B