Please view attached file that shows part of the MCAT book’s calculation to pulley system question. I understand all the physics theory behind the question and answer, but I am lost on the math. 1) I would like to know what is the name of the math theory where you can just add two different physics equations together and 2) when I am doing physics questions how do I know when I can/should be able to add two different physics equations together? I used to be a strong physics and math student, but over time I forgot my high school theories . 3) My biggest problem in calculating physics problems is knowing when to apply certain math theories that I have learned from a different high school textbook and teacher. In my physics textbook there is a math review/foundation section in the back of the book. I have gone over the physics math review section and understand the entire basic math. But occasionally there will be math theories/understandings that creep up in long and complex physics calculations where I got the final answer wrong because I forgot how to apply a certain math theory and I am competent on the physics theories. I can review my old high school math notes, but there are many math theories that will not be used in MCAT physics, so I would be wasting my time reviewing high school math. Please advise what I should do to be stronger in MCAT physics math or if there is a website where I can practice more MCAT physics math, so I know what type of math theories apply towards specific physics questions or topics i.e. memorize certain math theories will be applied in certain MCAT physics calculations? Thank you for your help and advice.