Algebra I: Algebra I: Introduction to Introduction to

Algebra Algebra

YoungMath and Expert Subjects.com Present

LESSON OBJECTIVES LESSON OBJECTIVES (A.3A;A.3B):(A.3A;A.3B):

•Define the purpose of Algebra

•Define Algebra

•Define variable

•Define algebraic expression

•Define algebraic equation

Why am I learning

this?

“Algebra looks so hard!”

•Algebra is everywhere!

•Teaches organization

•Simple way of expressing a question to enable you to find the answer faster

•Sharpen your reasoning (problem solving) skills

•Prepare your for higher learning

What is algebra?What is algebra?The part of mathematics in which

letters and other symbols are used to represent unknown numbers and

quantities in formulas and equations.

1. If there are 4,000 widgets in a mile, how long is a widget (in inches)?

2. If the temperature outside is 25° F, what is the temperature in degrees Celsius?

What is the What is the unknown unknown valuevalue??

What’s the unknown in example 1? Length of a widget in inches

What is the unknown in example 2? Temperature in degrees Celsius

In algebra, we use variables to represent unknown values.

Variable: 1. *A symbol (frequently a letter) used to represent

an unknown value;2. An element, feature, or factor that is liable to

vary or change

Expressions vs. EquationsExpressions vs. Equations

Question: What is the difference between an expression and an equation?

Language Arts- phrase and a sentence◦ Phrase does not convey meaning

Ex: “down the street”◦ Sentence is complete thought

Ex: “I went down the street.”

Expression is a mathematical “phrase”• Ex: 4+3

Equation mathematical “sentence”• Ex: 4+3 = 7

Algebraic Algebraic Expressions & EquationsExpressions & Equations

Definition: mathematical expressions and equations the use a variable

Example of algebraic expressions:

• 4x + 7•7y

• 2 + θ•α / 6σ

Example of algebraic equations:

• 4x + 7 = 9•7y = 49

• 2 + θ = 45 •α/6σ = 546

Cannot be solved; only simplified if possible

Ex: 4 + 9 – b13- b

Can be solved to determine the value of the variable

Ex: 3x =12 x = 4

LESSON OBJECTIVES LESSON OBJECTIVES (A.3A;A.3B):(A.3A;A.3B):

•Define the purpose of Algebra

Simple way of expressing a question to enable you to find the answer

faster

•Define Algebra

The part of mathematics in which letters and other symbols are used to

represent unknown numbers and quantities in formulas and equations.

•Define variable

A symbol (frequently a letter) used to represent an unknown value

•Define algebraic expression

A mathematical “phrase” in which letters and other symbols are used to

represent unknown numbers and quantities (Does not convey meaning!)

•Define algebraic equation

A mathematical “sentence” in which letters and other symbols are used to

represent unknown numbers and quantities (complete thought!)