which equation demonstrates the multiplicative identity property

An equation is any expression with an equals sign, so your example is by definition an equation. 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 ... The confusion here seems to be about how translation and other transformations apply to the equation of a circle, which is not a function in the sense of passing the vertical line test but rather an implicit relation. Let's clear up the confusion: Translation: For the circle's equation $ (x - x_1)^2 + (y - y_1)^2 = r^2 $, the $ x_1 $ and $ y_1 $ terms represent the coordinates of the center of ...