Answer:
B
Explanation:
if a polynomial f(x) is divisible by (x - a) , then f(a) = 0
for the polynomial to be divisible by (x - 3) then the polynomial will equal zero when x = 3 , that is
3³ - 9(3)² + 3n - 12 = 0
27 - 9(9) + 3n - 12 = 0
27 - 81 + 3n - 12 = 0
3n - 66 = 0 ( add 66 to both sides )
3n = 66 ( divide both sides by 3 )
n = 22