Answer:
$24.96
Explanation:
The question was incomplete. If you are asking how much is the book worth after 8 years, here's how to do it
Original cost = $58
Since the rate of decrease = 10%, the cost of the book after 1 year is 90% of the original price
90% = 90/100 = 0.9
Therefore after 1 year, the book cost is 58(0.9)
After another year(effectively 2 years) the above cost will drop by another 10% to 90% of the first year value: 58(0.9)(0.9) = 58(0.9)²
So the value of the book after a period of n years is modeled by the function
V = 58 (0.9)ⁿ
After 8 years the value is
58 (0.9)⁸ = 58 x 0.43046721
V = $24.96 rounded to the nearest cent