Answer:
Step-by-step explanation:

Area of a circle = πr²
Radius = 18/2 = 9
A = (3.14)(9)²
A = 254.34
Hope this helps :)

The difference is the result of a subtraction problem.
We are given two values that are being subtracted: 54 and a number, represented by 
So, represent this mathematically with
.
Answer:
A relation is a function if the x-values map to only one y-value. In other words, if a relation is one-to-one or many-to-one it is a function.
Step-by-step explanation: