Question

Each day that a library book is kept past its due date, a $0.30 fee is charged at midnight. Which ordered pair is a viable solution if x represents the number of days that a library book is late and y represents the total fee?
(–3, –0.90)
(–2.5, –0.75)
(4.5, 1.35)
(8, 2.40)

Answer 1

Each day that a library book is kept past its due to date , a $ 0.30 free is charged at midnight.
x represents the number of days that a library book is late and y represents the total fee.

e.g., total fee = number of days × charge rate
y = 0.3x

check (-3, -0.9) means, y = -0.9 , x = -3 => y = 0.3x is satisfied (-3,0.9)

similarly, (-2.5 , -0.75) , (4.5, 1.35) and (8, 2.40) satisfied equation y = 0.3x

hence, equation y = 0.3x represents this phenomenon. so, answer is y = 0.3x