1. Algebra I 1.1 Evaluate Expressions

2. Question: How do you evaluate algebraic expressions and powers? Answer: By substituting numbers in for the variable and performing the indicated operation(s)

3. Vocabulary Variable — a letter used to represent one or more numbers Expression--numbers, variable, and operations (ex: mn) Algebraic Expression — an expression that includes at least one variable

4. Section 1.1 EVALUATING AN EXPRESSION WITH ONE OR MORE VARIABLES Please look at the handy chart below & let’s talk it out: Algebraic Expression Real Meaning Operation Used 5(n) 5·n 5n5 times nMultiplication 14/y 14÷y14 divided by yDivision 6 + c6 plus cAddition 8 – x8 minus xSubtraction

5. a. 13 n =13 3 Substitute 3 for n. =39 Multiply. b. 9/n =9/3 Substitute 3 for n. =3 Divide. c. n -1 = 3 - 1 Substitute 3 for n. =2 Subtract. d. n + 8 = 3 + 8 Substitute 3 for n. = 11 Add. Evaluate algebraic expressions Evaluate the expression when n = 3.

6. Let’s Practice Let y = 2 1.6y 2.8 divided by y 3.y + 4 4.11 take away y

7. If you know how much it costs ($360) and how much you earn each week, you can determine how many weeks it will take you to save enough $$$. You earn about $64/week, how many weeks will it take you to buy your iPhone? Here’s the situation: You’re saving money to buy an iPhone… $399 You can do this by EVALUATING AN EXPRESSION THAT INVOLVES A VARIABLE: 64w = ?

8. Section 1.1 EVALUATING AN EXPRESSION WITH ONE OR MORE VARIABLES Evaluate the expression BELOW when: w = 2, w = 3, w = 4… until you get an answer. 64w = ? 64(2) = 128 64(3) = 192 64(4) = 256 64(5) = 320 64(6) = 384

9. Section 1.1 EVALUATING AN EXPRESSION WITH ONE OR MORE VARIABLES The total cost of seeing a movie at a theater can be represented by the expression a + r where a equals the cost of admission (in dollars) and r is the cost (in dollars) of refreshments. Let’s say you pay $7.25 for admission and $7.50 for refreshments. Find the total cost. total cost = a + r = 7.25 + 7.50 = 14.75

10. Vocab Power — an expression that represents repeated multiplication of the same factor Exponent — the number of times the base gets repeated Base — the number that is multiplied as many times as the exponent

11. PowerWordsProduct 7 1 Seven to the first power 7 5 2 Five to the second power 5 (1/2) 3 One half to the third power -OR- one half cubed ½ ½ ½ Z 5 Z to the fifth powerzzzzz

12. More Practice… Write in words and expand using numbers 1.9 5 2.2 8 3.N 4 4.x 3 when x = 8 5.k 2 when k = 2.5

13. Section 1.1 EVALUATING AN EXPRESSION WITH ONE OR MORE VARIABLES Each edge or side of a medium sized pop-up storage cube is 14 inches long. The storage cube is made so that it can be folded flat when not in use. Find the volume of the storage cube. 14 in. V = s 3 = 14 3 = 2,744 The volume of the storage cube is 2,744 cubic inches.

14. Closer How do you evaluate an expression that contains variables? You substitute the values of the variable in the expression and simplify the resulting numerical expression.