>>11841607Mathematical expressions are ways of paraphrasing a sentence in a normal language.
If lucy has 3 apples and john has 4 apples, a faster way of writing this would be
X = 3
Z = 4
This is not a perfect translation since some information is lost, but on the flip side it's easier to work with since you're only retaining the information you care about.
If you want to find out how many apples they both have you just write
3 + 4
There are no rules on how to translate a scenario to a mathematical expression. It's completely your artistic choice. You just need to have some intuitive idea you want to express, and then you need to find the right the right kind of mathematical situation to use to express it. Once you found math that behaves in a similar way to your scenario, then you can manipulate the math to simulate manipulating the scenario. If you need new math you can invent it.