Question

Given f(x) = x2 + 5x + k, and the remainder when f () is divided by x – 8 is

93, then what is the value of k?

Answer 1

By the remainder theorem, the remainder upon dividing a polynomial p(x) by x - c is equal to p(c).

Here, p(x) = x² + 5x + k and c = 8, which gives

p (8) = 8² + 5•8 + k

93 = 64 + 40 + k

k = -11