👉 In mathematics, "co-adding" or "co-simplifying" means to reduce a mathematical expression by adding or subtracting terms. This is similar to simplification in other areas of mathematics but with different rules and terminology. For example, consider the following equation: \[ a + b = c \] If we want to simplify this equation by combining like terms (terms that have the same variable raised to the same power), we would add or subtract the coefficients of the variables.