Notice carefully:
8=D is the formula for the penis.
Putting this formula in parentheses () symbolizes insertion into the vagina.
Since all life comes from this magical union of the genitals, (8=D) is the universal mathematical representation of the dirty deed.
You know what it is! It's a STIFFIE!!!! hahaha! All you have to do is go up to someone and say "eight equals Dee" and they wont know what the fuck your saying! It gives a boring day a little boost of fun! If you know what I mean.