18 is what percent of 48? Please explain step by step to get marked

Question:- 18 is what percent of 48?

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a

step-by-step explanation:

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