Answer:
k = 3
Step-by-step explanation:
Given that y and x are directly related then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 81 when x = 27
k =
=
= 3
Answer:

Step-by-step explanation:
An expression means that we don't know enough to create an equation. So, this means we will mostly be using variables.
John runs r amount every day. We need to create an expression for if he runs r amount for 4 days.

r = how much he runs per day
4 = how many days he runs
z = how much he runs this week
This is your expression!
Answer:
(0,0)
Step-by-step explanation:
For the x coordinate it is at 0 and for the y it is also at 0.