Answer:
y = -3
Step-by-step explanation:
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:
The answer is b
Step-by-step explanation:
Answer:
The two lines are not parallel.
Step-by-step explanation:
Every linear equation follows this structure:
y = mx + b
y is the y value
x is the x value
m is the gradient/slope of the line
b (or sometimes c) is the y-intercept of the line
Firstly, we have to get the y term on one side by itself.
6x + y = -1
-6x -6x
y = -6x - 1
-2x -5y = 1
+2x +2x
-5y = 2x + 1
Secondly, we make it so the y term is just the y value.
The first equation is already like this, so we don't need to do anything to that.
-5y = 2x + 1
÷ -5 ÷ -5
y = (2x + 1) / -5
This can be expanded and simplified to:
y = -2/5x - 1/5
Thirdly, we have to compare the slopes and y-intercepts.
y = -6x - 1
y = 2/5x - 1/5
If the slopes are the same and the y-intercepts are different, they are parallel. However, the slopes are different, therefore they are not parallel.