1-2 Algebraic Expressions

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1-2 Algebraic Expressions

• Objectives
• To evaluate and simplify algebraic expressions

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Subsets of Real Numbers
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Subsets of Real Numbers

• Natural Numbers 1, 2, 3, used for counting
• Whole Numbers 0, 1, 2, include zero
• Integers -2, -1, 0, 1, 2 include opposites
• Rational Numbers 7/5, -1/2, 0.25, 3
• Can be written as a fraction
• Decimal will either repeat or terminate
• Irrational Numbers , ?, 1.011011101111
• Cannot be written as a fraction
• Decimal will not repeat or terminate

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Definitions

• Variable symbol usually a letter that represents
  one or more numbers
• Algebraic Expression expression that contains
  one or more variables
• Evaluate substituting numbers for variables in
  an expression and following order of operations

What are order of operations???
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Review

• Simplify the following using order of operations

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More Definitions

• Term number, variable, or product of one or more
  variables
• Coefficient the numerical factor in a term
• Like Terms have the same variables raised to the
  same powers

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Example 1
Evaluate 7x 3xy for x 2 and y 5.
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Example 2
CAUTION! -32 ? (-3)2 -x2 ? (-x)2

• Evaluate x2 2(x 1) for x 3

How many negatives? -x2 , (-x)3 ,-x5 , (-x)6 ,
(-x)4 , -x10
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Example 3

• Simplify by combining like terms
• 2x2 5x 4x2 x x2
• y(1 y) 3y2 (y 1)

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Example 4

• Find the perimeter of the figures and simplify
  the answer.

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Summary Questions

• Subtraction is the same as adding a ________.
• Division is the same as multiplying by ______.
• Whats the distributive property?
• What happens when you multiply by 0? -1?
• What does (ab) equal?
• What happens when you take the opposite of an
  opposite?

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HomeworkPgs. 16-17 38-53, 67 a,b