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Slope of the line

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

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            \"\"

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\"\"

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Substitute \"\" in slope formula.

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\"\"

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\"\"                (Signs are same. So, product is positive)

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\"\"

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\"\"       (Find the cross products: If \"\" then\"\")

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\"\"(Distributive property: \"\")

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\"\"        (Multiply: \"\") \ \

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\"\"               (Add: \"\") \ \

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\"\"    (Add 24 to each side)

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\"\"                         (Add:\"\")

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\"\"                    (Divide each side by 4)

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\"\"                         (Cancel common terms)

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\"\"                              (Divide: \"\")

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\"\"

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The value of r is \"\".

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