Question

When writing an expression or equation to represent A real world situation, why is it important to be able to describe what each part of the expression or equation represents

Answer 1

So that other people can figure out whether your models (built using equations and variables) can make accurate predictions. Good equations should be able to make accurate predictions, and scientists should be able to use them consistently. Good equations come with axioms, definitions and descriptions that mathematicians and scientists alike can understand.