Answer
Not factorable by grouping
Work Step by Step
$3x-3+x^{3}-4x^{2}=3(x-1)+x^{2}(x-4)$
There is no common binomial factor that can now be factored out. No matter how we rearrange the terms, no grouping will lead to a common factor. Thus, this polynomial is not factorable by grouping.
