Question

Given f(x) = 3x2 + kx + 19, and the remainder when
f(x) is divided by x + 3 is 37, then what is the value of k?

Answer 1

Answer:

$f{x} = x + 3 = 0 \\ x = - 3 \\ f( - 3) = 3( - 3) {}^{2} + k( - 3) + 19 = 37 \\ f( - 3) = 27 - 3k + 19 = 37 \\ f( - 3) = 46 - 3k = 37 \\ f( - 3) = 46 - 37 = 3k \\ f( - 3) = 9 = 3k \\ f( - 3) = k = 3$