50g

Back in the old days(early 90's) at San Diego State University I used 
an HP27S to get awesome grades in all of my statistics and business 
classes.  I and a few of my study buddies would enter all kinds of 
equations within equations with tons of variables before every test. 
The instructors actually encouraged us to do this.  One time, while I 
was doing an intership at the IRS, I even created an equation that 
would figure out your taxes (1040 with deductions and more!).  All of 
these equations were lost many years ago because I would always 
forget to replace the batteries.

Anyway, the solver on the 27s was fairly simple to use compared to 
what is on the HP50g.  I love the way a 50g can create graphs and the 
feel of the buttons.  I've learned to use the equation writer and it 
is great at displaying equations in textbook style!  But, I've yet to 
figure out how to write a simple equation and retrieve it for later 
use.  For example, I'd like to enter the quadratic equation and be 
able to use it from time to time.  Any pointers would be greatly 
appreciated.  I do have a copy of the User's Manual and User's Guide 
in .pdf form.

Quadratic Equation (one each for +/-):

1. 
x=(-b+Sqrt(b^2-4ac))/2a

2.
x=(-b-Sqrt(b^2-4ac))/2a

Thanks in Advance