1. Pre Test Translate each word into a mathematical operation.+
1) increase +
6) plus −
2) decrease −
7) difference ÷
3) more than +
8) quotient +
4) less than −
9) sum •
5) product •
10) times
Write and answer the following problems.
11) Simplify. −42
12) Write 2y • 2y • 2y in exponential form.

2. 1-1 Variables and Expressions
You would be wise to listen carefully and take notes!
Be smart -correct your odd homework problems after you complete them!
Algebra Glencoe McGraw-Hill Linda Stamper

3. In algebra, variables are symbols used to represent unspecified numbers or values. Any letter may be used as a variable.
An expression that represents a particular number is called a numerical expression.
Example:
An algebraic expression consists of one or more constants and variables along with one or more arithmetic operations.
constants - numbers
variables - letters
operations - addition, subtraction, multiplication and division
Example of an algebraic expression: 3x + 2

4. In algebraic expressions, a raised dot or parentheses are often used to indicate multiplication as the symbol x can be easily mistaken for the variable x. Here are some ways to represent the product of x and y.
Use good form in an answer!
In each expression, the quantities being multiplied are called factors, and the result is called the product.

5. An expression like 43 is called a power.
base 
 exponent
or power
word form: four to the third power
four cubed
factor form: 4 • 4 • 4
evaluated form: 64
To evaluate an expression means to find its value.
The word power can also refer to the exponent.

6. Writing Algebraic Expressions
In English there is a difference between a phrase and a sentence. Phrases are translated into mathematical expressions. Sentences are translated into equations or inequalities.
Phrase
The sum of 6 and a number
6 + n
Sentence
The difference of a number and three is five.
n – 3 = 5
Sentence
Seven times a number is less than 50.
7n < 50
When choosing a variable for an unknown, it may be helpful to select a letter that relates to the unknown value (for example: let a represent age). If a variable is given use it!
Sentences must have a verb!
Sentences must have a verb!

7. Would you say 5 notebooks or notebooks 5?
The product of five and a number 5n
The product of a number and five
Would you say 5 notebooks or notebooks 5? 5n
Write your answer in good form - the number comes before a variable in a term involving multiplication.

8. Use a fraction bar to designate division!
Write an algebraic expression for each word phrase.
a. The difference of a number and 7
n – 7
b. 32 increased by a number
32 + n
c. 25 less than a number 25 n –
d. 10 less the product of 5 and a number cubed
10 – 5n3
e. The quotient of a number and six. n 6
Use a fraction bar to designate division!

9. Did you use a fraction bar to designate division?
Example 1 Write the phrase as an algebraic expression.
a. 11 greater than a number
Did you use a fraction bar to designate division?
n + 11
b. a number subtracted from 15
15 – n
c. The sum of a number and 30
n + 30
d. Maria’s age minus 27
a – 27 18 n
e. The quotient of 18 and a number
f. The sum of a number and ten, divided by two.

10. Example 2 Write the phrase as an algebraic expression.
a. eight more than a number
n + 8
b. seven less the product of 4 and a number x
7 – 4x
c. n cubed divided by 2
d. 9 more than the quotient of b and 5
e. one third the original area of a
f. thirteen less than a number
n - 13

11. Write in exponential form (as a power).
Example 3
Example 4
Example 5
y • y • y • y
3x • 3x • 3x • 3x
5 • 5 • 5 y4 53
(3x)4
Evaluate.
Example 6
Example 7
Example 8
2 • 2 • 2 • 2
5 • 5 • 5
-32
(-3)2 16
125 -9 9
Must have parentheses!
A power applies only to what is directly in front of it.

12. Pre Test
Write and answer the following problems in your spiral notebook.
1) Simplify. −42
2) Write 2y • 2y • 2y in exponential form.
−16
(2y)3
− 4 • 4
A power applies only to what is directly in front of it.
The 2y must be in parentheses!

13. Homework
1-A2 Pages 8–9, #13–29,46–54.