\"\"

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The equation  \"\" represents a constant rate of change and k is the

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constant of variation.

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Compare the equation  \"\" with equation \"\".

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 The constant of variation is \"\".\"\"

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The slope m of a non vertical line through any two points is given by,

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\"\" 

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\"\"         (Substitute  \"\")

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\"\"         (Additive indentity property: \"\")

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\"\"               (Additive indentity property: \"\")      

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  Slope \"\".

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\"\"

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The slope m of the line that passes through the pair of points is \"\".