$\"\"$

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From the diagram the angles are $\"\"$ .

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In a quadrilateral sum of angle measures is $\"\"$ .

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$\"\"$

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$\"\"$ (Remove brackets)

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

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$\"\"$ (Simplify: $\"\"$ )

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$\"\"$

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$\"\"$ (Subtract 39 from each side)

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

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

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$\"\"$ (Subtract: $\"\"$ )

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$\"\"$

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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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So, the angle measures are $\"\"$ . $\"\"$

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The value of x is $\"\"$ . The angle measures are $\"\"$ .