Sam and her sister both open savings accounts. Each begins with a balance of zero dollars. For every 5 dollars that Sam saves her sister saves 2 in her account. If Sam saves 40 dollars how much did Sam's SISTER save? *

answer: hence, function will be

explanation:

since we have given that

cost of a new textbook = $85

according to question, the resale value of a textbook decreases by 25% with each previous owner,

so, our function becomes,

here, y is the total value of the text book after x owners.

hence, function will be

the answer is  

c.

90.0π cm^2

hope you got it.