I'm assuming this is for the new Year 11 syllabus?

If so, using the word "denominator function" is perhaps the cause of ambiguity here. The idea is that you should start with the sketch of \( (x+4)(x-4)\), and then *use* that curve to sketch \( \frac{1}{(x+4)(x-4)} \).

Then, you apply the multiplication technique on \(-3x\) and \( \frac{1}{(x+4)(x-4)}\).

(So in step 1, the original function is indeed \((x+4)(x-4)\). But in the second step, because we're doing a multiplication, there's technically speaking *two* "original" functions.)

Not sure how \(-3x(x+4)(x-4)\) would be useful here, unless it's just a misinterpretation, or a typo.