Warm Up

Brainstorm words that are associated with:

Symbol Associated Word

+

-

x

÷

Variables and Expressions

Section 1.1

TSWBAT◦ Convert word phrases into algebraic

expressions and back.◦ Write a rule that describes a pattern.

Objective

Quantity Variable Algebraic Expression Numerical Expression

Vocabulary

Associated Words

Symbol Associated Word

+ Add, added to, sum, increase, more then, total, plus

- Minus, subtract, subtracted from, less then, decrease

x Multiply, times, product, of (for fractions)

÷ Divide, divided by, quotient, over (for fractions)

Convert the following phrases in to algebraic expressions

25 more then a number nAnswer: n + 25

74 less then a number nAnswer: n – 74

Example 1

18 more then a number n

7 minus a number n

The sum of a number n and 8

9 plus a number n

Practice

What is the algebraic expression for the verbal phrase:

5 times a number nAnswer: 5n

The quotient of a number n and 7Answer: n/7

Example 2

6 times a number n

The quotient of 18 and a number n

The product of a number n and 3

6 divided by a number n

Practice

Example 3

What is the algebraic expression for the word phrase

8 less then the product of a number x and 4.Answer:4x – 8

Twice the sum of a number x and 8.Answer:2(x + 8)

The quotient of 5 and the sum of 12 and a number x.Answer:

x12

5

Example 4

Write a verbal phrase you can use to represent the algebraic expression.

X + 8.1

10x + 9

5x – 1

3

n

Example 5

The table shows how the cost of renting a scooter depends on how long the scooter is rented. What is a rule for the total cost? Give the rule in words and as an algebraic expression.Answer: 7.5h + 10

Hours Cost

1 $17.50

2 $25.00

3 $32.50

4 $40.00

5 $47.50

Pg. 7 # 10-40 even, 47-48, 56-66

Assignment