Factorize the quadratic expression 3f2 - 13f + 4.

The expression is in the form $af^2 + bf + c$, where $a=3$, $b=-13$, and $c=4$.

We need two numbers that multiply to $a \times c = 3 \times 4 = 12$ and add up to $b = -13$.
The two numbers are $-1$ and $-12$, because $(-1) \times (-12) = 12$ and $(-1) + (-12) = -13$.

Group the terms and factor out the common factors from each pair.

Factor $f$ from the first group and $-4$ from the second group.

Now, $(3f - 1)$ is a common factor.