So just about everyone knows the half plus seven rule. (Well not everyone, but many people. In short: “Don’t date someone less than half your age plus seven years.” If you are in the age range where this breaks down mathematically, then you can wait a few years to start dating.)
Well inherent in that rule is this set of equations:
o = older person’s age
y = younger person’s age
n = number of years until a given match is acceptable

The rule itself*:
.5*o+7=y

The rule from the younger person’s view point:
2y-14=o

and how many years it will be before an (o,y) grouping won’t be a little creepy anymore:

o-2y+14=n
(for values of y where y< .5o+7)

This is what happens when I get bored and I have an equation that models a situation.
So any other interesting things you can do with this set of equations that I’m missing?

* By rule, of course, I mean guideline.

*edit*
There was an error in equation 2, pointed out to me by