Essentially, you are using Maxwell's equations right now, even if you don't know it. Why are they called "Maxwell's equations"? That's after James Clerk Maxwell.

Solving equations using iteration – Higher tier Approximate solutions to more complex equations can be found using a process called iteration. Iteration means repeatedly carrying out a process.

A new equation using age and sex and omitting race underestimated measured GFR in Blacks (median, 3.6 ml per minute per 1.73 m 2; 95% CI, 1.8 to 5.5) and overestimated measured GFR in non-Blacks ...

We also aimed to show that further accuracy could be achieved by using the arithmetic mean of a serum creatinine–based equation and a cystatin C–based equation to estimate GFR. 8-12 ...

The expanded accounting equation builds upon the basic accounting equation's use of assets, liabilities and equity by incorporating additional components such as revenues, expenses and withdrawals ...