Answer
$(3x-1)(4x^2+1)$
Work Step by Step
The given expression can be written as:
$4x^2(3x-1)+(3x-1)$
The $GCF$ for the two terms is a binomial, $(3x-1)$. Even though it is a binomial, we can factor it out just like we would factor out a number or a variable. Thus, we factor out the binomial to obtain:
$=(3x-1)(4x^2+1)$