$\"\"$

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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 $\"\"$ in slope formula.

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$\"\"$

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$\"\"$

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$\"\"$ (Subtract: 8 – 4 = 4)

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$\"\"$ (Multiply each side by (x – 2))

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$\"\"$ (Cancel common terms) $\"\"$

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$\"\"$ (Apply distributive property: a (b – c) = ab – ac)

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$\"\"$ (Multiply: $\"\"$ )

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$\"\"$ (Add 1 to each side)

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$\"\"$ (Apply additive inverse property: $\"\"$ )

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$\"\"$ (Subtract: 4 – 1 = 3) $\"\"$

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$\"\"$ (Multiply each side by negative 2)

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$\"\"$ (Cancel common terms)

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$\"\"$ (Multiply: $\"\"$ ) $\"\"$

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The value of $\"\"$ .