Given two circles whose radii are 5" and 15", the ratio of their areas is

The answer to your question is ratio = 9

Step-by-step explanation:

Data

Circle 1 radius = 5''

Circle 2 radius = 15''

Process

1.- Calculate the area of circle 1

Area = πr²

Area = π(5)²

Area = 25π

2.- Calculate the area of circle 2

Area = πr²

Area = π(15)²

Area = 225π

3.- Calculate the ratio of the areas

ratio = 225π / 25π  

       = 9

the revenue of the fitness center, y, is the product of two factors: the number of members and the fee paid by each member. there are 320 members now, but number of members goes down by 10 for each $5 increase in fees, so if x is the number of $5 price increases then members is equal to (320 - 10x). since the fee is currently $45, and the fee increases by $5 for every price bump x, the fee is given by (45 + 5x). so, revenue y is given by y = (320 - 10x)(45 + 5x).