equivalentANSWER

2, 3ANSWER

Prerequisite Skills VOCABULARY CHECK

Copy and complete the statement.

23

1. In the fraction , is the numerator and is the denominator.

? ?

2. Two fractions that represent the same number are called fractions.?

100ANSWER

3. The word percent (%)means “divided by .”

?

Prerequisite Skills SKILLS CHECK

Perform the indicated operation.

4. +23

35

5. –56

34

6. 35

25

7. 12

58

ANSWER 1

154

ANSWER 112

ANSWER 25

ANSWER 45

9. 23%

8. 4%

Prerequisite Skills SKILL CHECK

Write the percent as a decimal.

ANSWER 0.23

ANSWER 0.015

0.04ANSWER

10. 1.5%

11. 2.5% ANSWER 0.025

Section 1.1Evaluating Expressions

• This chapter introduces a lot of vocabulary and basic concepts for algebra.

• Vocabulary will play a very important role in this class.

• You are expected to take notes over both vocab. and examples.

Section 1.1 Evaluating Expressions

• Key Vocabulary– Variable– Algebraic expression (variable expression)– Power– Base– Exponent– Squared & Cubed

Substitute 3 for n.Multiply.= 39

Subtract.= 2Substitute 3 for n.

Substitute 3 for n.

= 3 Divide.

EXAMPLE 1 Evaluate algebraic expressions

Evaluate the expression when n = 3.

a. 13 n = 13 3

93

b. 9n

=

c. n – 1 =

Substitute 3 for n.

Add.= 11 d. n + 8 =

3 – 1

3 + 8

EXAMPLE 2 Evaluate an expression

Movies

The total cost of seeing a movie at a theater can be represented by the expression a + r where a is the cost (in dollars) of admission and r is the cost (in dollars) of refreshments. Suppose you pay $7.50 for admission and $7.25 for refreshments. Find the total cost.

Add.

The total cost is $14.75

ANSWER

Substitute 7.50 for a and 7.25 for r.

= 14.75

= 7.50 + 7.25

Write expression.Total cost =

EXAMPLE 2 Evaluate an expression

SOLUTION

a + r

EXAMPLE 4 Evaluate powers

Evaluate the expression.

a. x4 = 24

= 16= (1.5)(1.5)(1.5)= 3.375

= 2 2 2 2b. n3 = 1.53

b. n3 when n = 1.5

SOLUTION

a. x4 when x = 2

GUIDED PRACTICE for Example 4

Evaluate the expression.

9. x3 when x = 8

9. x3 = 83

= 512= (2.5)(2.5)(2.5)= 15.625

= 8 8 810. k3 = 2.53

10. k3 when k = 2.5

SOLUTION

SOLUTION

EXAMPLE 5 Evaluate a power

Storage cubes

Write formula for volume.

= 143 Substitute 14 for s.

= 2744 Evaluate power.

Each edge of the medium-sized pop-up storage cube shown 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.

V = s3

The volume of the storage cube is 2744 cubic inches.

• Assignment: P. 5 1,2, 4-44 evens only, 49-52 all

Put some work on your paper – show where the answer came from.

Use a calculator only when large numbers are involved (like 64) – otherwise, use that calculator in your head!!