The SAT does not require the memorization of many formulas. Most of them will be on the geometry section. However, there are two that occasionally come up with algebra questions. 

 

Distance Formula

Distance = rate X time

 

It takes Tom 2.5 hours to bike to work at rate of 12 mph.  Assuming that the same route is taken with no stopping, how long will it take him to get home at twice the rate?

 

This is easy to solve once you know that you need two parts to get the final answer. 

 

Population/Interest Formula

Another formula is...

 

I = P * r * r

 

or

 

Interest Earned = Principal * rate * years

 

There are many other formulas out there, of course, but these two are the most common that will be encountered on the SAT math section.