-7x+6y-6x is simplified to be -13x+6y.
For this case we have the following function:

By the time the stone is thrown, x = 0.
We must evaluate this value of x in the function.
We have then:
Answer:
The height of the stone at the time is thrown is given by:
h (0) = 15 meters
Answer:
B is your correct answer
Step-by-step explanation:
Answer:
Variable rate of change.
Step-by-step explanation:
Plot the points and you'll see that the graph is not a straight line, therefore the rate of change is variable.
Use a calculator called symbolab.com 0-0