What does x equal to​

answer:   (s+1)(s+4)

step-by-step explanation:

factor s2+5s+4

s2+5s+4

=(s+1)(s+4)

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