Which binomial is a difference of squares?

14x^2 – 81

16x^2 + 81

25x^2 – 81

36x^2 + 81

Question

Which binomial is a difference of squares?

       14x^2 – 81

       16x^2 + 81

       25x^2 – 81

       36x^2 + 81

kc_kennylau · Answer

Any idea?

anonymous · Answer

What do you think it is

anonymous · Answer

Which ones can you eliminate right away?

mathmale · Answer

What does a "difference" look like?  A "sum?"

mathmale · Answer

iambatman's suggestion that you eliminate certain of the four possible answers is a really good one.

kc_kennylau · Answer

Well first it has to be a difference and second it has to be conistsed of squares

miracrown · Answer

First of all, both the first number and the second number must be perfect squares. secondly, it must be a difference thus, a minus sign.
Using these rules, can you identify the correct binomial?

miracrown · Answer

@NightmareNight

anonymous · Answer

Hint: A number made by squaring a whole number, is a perfect square :)

kc_kennylau · Answer

Looks like nightmarenight doesn't want to answer.

anonymous · Answer

Well in that case...to the batmobile, and onto a different question!

nightmarenight · Answer

I was afk.

but jeez, i wouldn't be posting the question if i could do that. @iambatman  @kc_kennylau @mathmale