It seems like systems of equation are part of almost every complex physics problem. What exactly are the rules or steps for solving such equations? I know how to solve a basic linear system of equations with two variables, but how do solve more complicated systems like non-linear systems of equations with more than two variables? How do you know if you have enough equations to find a solution? I feel like I didn’t spend enough time in math on these sorts of things for the sorts of problems given in physics.