Grade 7 Module 9- Properties of Equality

Addition Property of Equality

Adding the same number to each side of an equation produces an equivalent equation.

Subtraction Property of Equality

Subtracting the same number from each side of an equation produces an equivalent equation.

Multiplication Property of Equality

Multiplying each side of an equation by the same nonzero number produces an equivalent equation.

Division Property of Equality

Dividing each side of an equation by the same nonzero number produces an equivalent equation.

Reflexive (or Identity) Property of Equality

A real number is always equal to itself.

Symmetric Property of Equality

If the numbers are equal, they will still be equal if the order is changed.

Transitive Property of Equality

If two numbers are equal to the same number, then the two numbers are equal to each other.

Substitution Property

If the numbers are equal, then substituting one for the other does not change the equality of the equation.