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Topic: Changing Subtractions to Adding Negative Numbers
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Posts: 11
From: Mountain View, CA
Registered: 11/11/13
Changing Subtractions to Adding Negative Numbers
Posted: Nov 11, 2013 9:34 PM
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In simplifying algebraic expressions, it seems convenient to change all subtractions to addition of the negative form of the terms. This enables the use of the associative and commutative properties of addition. For example,
2x-2-x-1 becomes 2x+(-2)+(-x)+(-1)
Then through commutation, I can get

Is this commonly done or do students have problems with this approach?

Can you suggest other methods?

Thanks, --John

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