Section 1.2

Basic Operations of Algebra

2

Fundamental Laws of Algebra

Commutative Law of addition:

Commutative Law of multiplication:

Associative Law of addition:

Associative Law of multiplication:

Distributive Law:

3

Name that Property

2) 3 6 7 7 3 6

1) 4 (5 ) (4 5)

3) 4 5 3 4 5 4 3

4

Operations with Zero

Let a represent a real number:

a + 0 =

a – 0 =

a x 0 =

5

Operations with ZeroLet a represent a real number not equal to 0.

0 a =

a 0 =

0 0 =

6

Order of Operations

Evaluate: 5 + 4 x 6 – 9 3

7

PEMDAS(“Please Excuse My Dear Aunt Sally”)

1) Perform operations within __________ _____________.

2) Perform operations involving ___________ (and _____________).

3) Perform operations involving __________________ or _____________, working left to right.

4) Perform operations involving __________________ or _____________, working left to right.

8

Examples

3

20( 12) 40( 15)1) 5 3(7 ( 1)) 2 6 2)

98 98

33) 2, 9, 1

( )

a b cwhere a b c

c c b