Answer:
remainder = 0
Explanation:
Using the remainder theorem
If f(x) is divided by (x - h) then the remainder is f(h)
Here f(x) = x³ - x² - 17x - 15 and h = 5 , thus
f(5) = 5³ - 5² - 17(5) - 15 = 125 - 25 - 85 - 15 = 0 ← remainder
Since remainder is zero then (x - 5) is a factor of f(x)