It shouldn't be hard...seeing as it's not asking you to solve anything. Now if they are asking you to simplify the expression, then I'd just stick with step 4. But honestly, this is just gibberish, not math.
I'm not well experienced in this type of maths, but as far as I know 8πx+x≠9πx (x=St.v), so step three would be the final step in simplyfying this expression (8πx≈25.12x, while 9πx≈28.26x. 28.26≠25.12, so 8πx≠9πx).
EDIT: For those of you thinking about arguing that I wrote 8πx+x the first time but then proved why only 8πx≠9πx, 8πx+x≈25.12+1=26.12≠28.26.
EDIT: For those of you thinking about arguing that I wrote 8πx+x the first time but then proved why only 8πx≠9πx, 8πx+x≈25.12+1=26.12≠28.26.