# algebraic expression examples

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```					Section 1.2 – Algebraic Expressions and Models
Numerical expression – numbers, operations, and grouping
symbols

25 = 22222        2 to the 5th power

5 facotrs of 2

Base – 2
Exponent – 5
Power – the expression 25

Example 1/ Evaluating Powers

a.    (-3)4 =

b.    -34 =

ORDER OF OPERATIONS

1. ______________________________________________

2. ______________________________________________

3. ______________________________________________

4. ______________________________________________

Example 2/ Using Order of Operations

1.) -4 + 2(-2 + 5)2              2.) -8 + 5(1 – (-3))3
Variable – a letter that is used to represent one or more numbers
Algebraic Expression – an expression involving variables

Example 3/ Evaluating an Algebraic Expression

Evaluate –3x2 – 5x + 7 when x = -2

Example 4/ Writing and Evaluating a Real-Life Model

You have \$75 and are buying some CDs that cost \$15 each.
Write an expression that shows how much money you have left
after buying n movies. Evaluate the expression when n = 2 and n =
3.

SIMPLIFYING ALGEBRAIC EXPRESSIONS
- To simplify algebraic expressions you must combine like terms.
Like terms are parts that have the same variable with the
same exponent. When combining like terms you add the
coefficients of the like terms together.
Like Terms                  Unlike Terms
2    2
6x , 2x                     6x, 2x2

Example 5/ Simplifying by Combining Like Terms
a.   7x + 4x
b.   3n2 + n – n2
c.   2(x + 1) – 3(x – 4)
Example 6/ Using a Real-Life Model
You want to buy either a CD or a cassette as a gift for each
of 10 people. CDs cost \$13 each and cassettes cost \$8
each. Write an expression for the total amount you must
spend. Then evaluate the expression when 4 of the people
get CDs.

Example 7/
Write an expression for the total monthly cost of phone
service if you pay a \$5 fee and \$0.08 per minute. Then,
find the cost if you talk 6 hours during the month.

HOMEWORK – ASSIGNMENT #2

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