I recently started a degree with Open University in Engineering (a distance learning course that's fully accredited in the UK but works for me as I move around while my wife works as a Postdoc, currently in Palo Alto). The book I've found that covers me from math basics (basically GCSE, so high school Maths) through to the more advanced topics I know I will need is Engineering Mathematics by K. A. Stroud. I'd highly recommend it. It contains a good number of exercises (and all solutions), covers all the topics I need, and progresses at a good pace. You can see the contents here: https://www.bloomsbury.com/us/engineering-mathematics-978135...