Introduction to Algebra

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Introduction to Algebra

• Katy Carol Pam

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Algebra

• is the mathematics of working with variables,
  patterns and functions

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• Variable
• a letter that stands for an unknown number in a
  mathematical expression.
• A variable can be any letter.
• Variable
• 2 x 5
• Additive constant
• Additive Constant
• A known number whose value does not change

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• Expression
• A mathematical sentence made up of variables
  and/or numbers and operations.
• 2 x 5
• (expression)

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What is the variable in each expression?

• n 7 10
• 15 y 8
• 3 X 4 p
• j 6 4

• n
• y
• p
• j

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Solving an ExpressionAddition

• Subtract the additive constant from both sides of
  the expression
• n 7 10 7 n 10
• - 7 - 7 - 7 - 7
• n 10 7 n 10 7
• n 3 n 3

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Solving an ExpressionSubtraction

• Add the additive constant to both sides of the
  expression
• n - 7 10
• 7 7
• n 10 7
• n 17

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Solve each expression

• x 9
• t 8
• n 19
• k 30
• f 47
• g 102

• x 2 11
• 9 t 17
• n 14 5
• k 10 20
• 42 f 89
• g 3 99

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Try some more on your own!

• Addition
• 1 digit
• www.321know.com/add18cx1.htm
• 2 digit
• www.321know.com/add27fx1.htm
• 3 digit
• www.321know.com/add38ix1.htm

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Try some more on your own!

• Subtraction
• 1 digit
• www.321know.com/equ18dx2.htm
• 2 digit
• www.321know.com/equ28fx2.htm
• 3 digit
• www.321know.com/equ38mx2.htm