шире контекст есть?

В реляционной модели данных (в реляционной алгебре) термин relation (отношение) — фундаментальное понятие реляционной модели данных.
Под отношением обычно понимают двумерную таблицу, состоящую из столбцов и записец.

My math teacher, 35 years ago stated "formulas are used in chemistry, in math we have equations". To this day, the word 'formula' in math seems wrong, but I'd accept it's used commonly.
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An equation is any expression with an equals sign. Equations appear frequently in mathematics because mathematicians love to use equal signs.

A formula is a set of instructions for creating a desired result. Non-mathematical examples include such things as chemical formulas (two H and one O make H2O), or the formula for Coca-Cola (which is just a list of ingredients).
Mathematicians have long since realized that when it comes to numbers, certain formulas can be expressed most succinctly as equations. For example, the Pythagorean Theorem a 2 +b 2 =c 2 can be thought of as a formula for finding the length of the side of a right triangle, but it turns out that such a length is always equal to a combination of the other two lengths, so we can express the formula as an equation. The key idea is that the equation captures not just the ingredients of the formula, but also the relationship between the different ingredients.

вроде бы нет - здесь как раз в чистом виде __инструкция__ по нахождению одной величины ("показатель") через другие ("вычисляется по зависимости...", "определяется отношением A к B")

ср. A formula is a set of instructions for creating a desired result.)