Answer:
The value of variable r in the equation
is 
Step-by-step explanation:
We need to find the value of variable r in the equation 
Step 1: Write the equation

Step 2: Subtract 4 on both sides

Step 3: Divide both sides by 4

So, The value of variable r in the equation
is 
Answer:
the value of c(30) is 21.2, which represents the customers final cost of $21.20
Step-by-step explanation:
d
Answer:
answer to the question is A