How do i solve k^2-7k-8/30-10k / k^2 +6k+5 /10k-30

If (x + 8) is a factor of f(x), which of the following must be true? both x = –8 and x = 8 are roots of f(x). neither x = –8 nor x = 8 is a root of f(x). f(–8) = 0 f(8) = 0