9. Consider the function f(x) = x² + 3x – 4.
Part A: What is the factored form of f(x)? Show
your work.
a.f(x) = (x + 1)(x – 4)
b.f(x) = (x - 1)(x + 3)
c.f(x) = (x + 4)(x - 1)
d.f(x) = (x − 2)(x + 2)