Thursday 23 May 2013

algebra precalculus - Why is $(5sqrt{5p}-3sqrt{5q})(5sqrt{5p}+3sqrt{5q}) equiv 5(5p-3q)(5p+3q)$?

I was working on the difference of two squares, $125p^2-45q^2$



Writing my answer, $$(5\sqrt{5}p-3\sqrt{5}q)(5\sqrt{5}p+3\sqrt{5}q),$$ onto Pearson, I got a popup that said my answer was equivalent to the correct answer but in incorrect form. Apparently, the correct answer is $$5(5p-3q)(5p+3q).$$




Why is that? I'm failing to see the intuition here.

No comments:

Post a Comment

real analysis - How to find $lim_{hrightarrow 0}frac{sin(ha)}{h}$

How to find $\lim_{h\rightarrow 0}\frac{\sin(ha)}{h}$ without lhopital rule? I know when I use lhopital I easy get $$ \lim_{h\rightarrow 0}...