If we format our work smartly, we can do Cramer’s Rule more efficiently. Esthetics matters. (I could have done the highlighting lighter. Hope it does not make it hard to read all the numbers. Maybe yellow would have worked better. But my handwriting — it is in eternal need of improvement.)
Note how we can easily find anything we need on the paper: our determinant, our work, our ratios, our final answers. Everything is lined up and organized. A place for everything, and everything in its place. And we used space as well as we used stuff, i.e., writing. Learn from Tufte. Learn from Apple.
What ideas do you have to organize your work, whether math, history, physics, chemistry, business?