Algebra probably won't play too much of a factor in chemistry aside from the fundamentals in figuring out an unknown quantity. How much it will impact you with calculus would be dependent on how much you remember. I took algebra/calculus about 18 years ago too, and to be honest, I don't remember very much of algebra and calculus has long left the building.
I probably wouldn't retake algebra again, but I would sit down with a textbook for a few weeks and see what came back to me to see where I stood.