1 2 ALGEBRAIC EXPRESSIONS AND MODELS I can

1. 2 ALGEBRAIC EXPRESSIONS AND MODELS I can evaluate algebraic expressions. I can simplify algebraic expressions by combining like terms.

ORDER OF OPERATIONS PEMDAS 1. Parenthesis 2. Exponents 3. Multiplication & Division 4. Addition & Subtraction

EXAMPLE 1: EVALUATING POWERS (-3)4 �(-3) ∙ (-3) 81 e m a s e h t e v a h er? e s e nsw h t l a il W -34 �- (3 ∙ 3 ∙ 3) -81

EXAMPLE 2: USING ORDER OF OPERATIONS

EXAMPLE 3: EVALUATING AN ALGEBRAIC EXPRESSION -3 x 2 – 5 x + 7 -3(-2)2 – 5(-2) + 7 -3(-2) – 5(-2) + 7 -3(4) - (-10) + 7 -12 +10 5 +7 when x = -2 How many operations? Break them up!

x 2 – 6 x + 14 (3)2 – 6(3) + 14 (3)(3) – 6(3) + 14 9 - 18 +14 5 when x = 3

EXAMPLE 4: REAL LIFE MODELING You have $50 and are buying tickets to a movie that cost $15. Write an expression that shows how much money you have left over after buying n tickets. Evaluate the expression when n = 2 and n = 3. $50 = original money $15 = cost of ticket n = number of tickets 50 – 15 n � 50 – 15(2) = $20 left � 50 – 15(3) = $5 left e ? h t e ings r t a t th a h W rtan po im

ALGEBRAIC EXPRESSIONS Coefficients Like Terms 2 x + 3 + 5 x Terms

EXAMPLE 5: COMBINE LIKE TERMS 7 x + 4 x � 11 x 3 n 2 + n – n 2 � 2 n 2 + n 6 y 2 + 4 x + 2 y 2 – 5 x � 8 y 2 – x What is alike? DON’T forget the sign before the term!!

CLASSWORK With a partner: �Textbook �Pg. 14 -15 20 -54 even 60 82 -88 even When you are finished: �Show me your work to get credit for the day. �Copy your homework from the board.