Ann Neidhardt

4-22-02

Properties of Algebra

Associative Property

~Any of the 3 numbers can be associated in different orders and they will still equal each other.

Multiplication: (a*b) c = a (b*c)

Addition: (a + b) + c = a + (b + c)

Inverse Property

~Any number times its inverse will equal 1 and any number added to its inverse will equal 0.

Multiplication: a * (1/a) = 1    and     a = 0

Addition: a + (-a) = 0

Commutative Property

~The numbers “commute” around the problem.  Whether you have “a” first or “b” first the answer will be the same.

Multiplication: a * b = b * a

Addition: a + b = b + a

Identity Property

~Any real number multiplied by 1 or added to 0 will always turn out to be that number.

Multiplication: a * 1 = a

Addition: a + 0 = a

Distributive Property

~ Distribute the “a” throughout the problem

Multiplication over subtraction: a (b – c) = a*b – a*c

Multiplication over addition: a (b + c) = a*b + a*c

Properties of Equality

Reflexive Property

~ Any Number will always equal itself

a = a.

Symmetric

~If one number equals another,

than the other number also equals the first.

If a = b, then b = a

Addition Property

If a = b and c = d, then a + c = b + d.

Transitive Property

If a = b and b = c, then a = c.

Multiplication Property

If a = b and c = d, then a * c = b * d.