$\"\"$

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The equation is $\"\"$

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According to addition property of equality: If a = b then a + c = b + c.

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$\"\"$ (Add 2n to each side)

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$\"\"$ (Apply commutative property)

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

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$\"\"$ (Add 7 to each side)

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

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$\"\"$ (Divide each side by 6)

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$\"\"$ (Cancel common terms)

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$\"\"$ \ \

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$\"\"$ (Cancel common terms)

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$\"\"$ \ \

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Verify:

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To check the solution, substitute $\"\"$ in original equation.

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$\"\"$ \ \

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

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

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Compare the values, the equation is true. The solution is $\"\"$ .

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$\"\"$ \ \

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The value of $\"\"$ .

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