$\"\"$

\

Substitute $\"\"$ in slope formula.

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$\"\"$

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$\"\"$

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Multiply each side by negative 14.

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$\"\"$

\

$\"\"$

\

$\"\"$

\

Add 10 to each side.

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$\"\"$

\

$\"\"$

\

$\"\"$

\

The value of r is 66.