How do you evaluate a expression 
579 

14.11.2007 

Thank you for your inquiry.
There is a lot of webpages about evaluating expressions. You should try for example the following:
http://www.me.vccs.edu/mathprep/Evaluating_an_Expression_or_Formula.doc
http://aaamath.com/equ723evaluate1variable.html
http://www.regentsprep.org/Regents/math/orderop/evalPrac.htm
