Math has that effect…. I’m over 70, and still haven’t figured out theproblem of cars starting at different times & speeds – when one willcatch the other up. Or tanks filling at the top and emptying at thebottom [at different rates] – when will the tank be full/empty…. Inever really gave a flying you-know-what. Algebra is a completelyalien ‘language’ which lost me on pag one: basic rules…minus tiimesminus or minus divided by minus = positive. A totally artificialintellectual exercise which is a complete turnoff. An especialstumbling block — no one can explain how you multiply, divide, ordo ANYTHING, a negative number of times.