Since we know that (x+7) is a factor, and since we know all of the coefficients are divisble by 5, we can write a factorization as
... f(x) = 5(x +7)(x² -6x +8)
Evaluating f(2), we find that f(2)=0, so 2 is another root and our factorization becomes ...
... f(x) = 5(x +7)(x -2)(x -4)
The roots of the function are x = {-7, 2, 4}.
