Download 2-6 Algebraic Proofs

Geometry Wed 10/15/14
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Warm-ups….Complete Guided
Reading Slide
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Discussion/Notes/Guided Practice
– Section 2.6 Algebraic Proofs
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Homework:
– Algebraic Proofs Practice Worksheet
After this section, you will be able to:
1. Use algebra to write two-column proofs
2. Use properties of equality in geometry proofs
Success Criteria: Q&A, Guided Practice, Homework
Guided Reading – pg 94
Property
Definition
Example
Reflexive
Symmetric
Transitive
Addition Property of
Equality
Subtraction Property
of Equality
Multiplication Property
of Equality
Division Property of
Equality
Substitution
Distributive Property
Please look at example 1 to see how these properties are used to
JUSTIFY WHY the problem can be solved.
Please read Pg. 95
2. What is a two-column proof (also called a formal proof)?
3. Copy Example 2 into your notes.
2-6 Algebraic Proofs
Pg. 94
What is deductive reasoning?
Reasoning that uses facts, definitions, and other
known information.
What is inductive reasoning?
Reasoning based on examples that you have
already seen.
Solve the following problem:
5x  7  42
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Why are you allowed to do those
steps? How do you know they work?
Writing an Algebraic Proof
#1
Statements
5x  7  42
Reasons
Writing an Algebraic Proof
#2
Statements
4( x  1)  x  13
Reasons