$\"\"$ $\"\"$ $\"\"$

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The word “sum” indicates addition and the symbol is ( $\"\"$ ).

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The word “equals” indicates the symbol ( $\"\"$ )

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$\"\"$

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The equation is $\"\"$ .

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$\"\"$

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According to subtraction property of equality: Subtract $\"\"$ from each side.

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$\"\"$

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$\"\"$ (Apply commutative property of addition: $\"\"$ )

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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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According to multiplication property of equality: Multiply each side by 6.

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$\"\"$

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$\"\"$ (Cancel common terms)

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

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

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$\"\"$ (Product of two same signs is positive)

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$\"\"$

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The number is $\"\"$ .