$\"\"$

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

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The equation is $\"\"$ .

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Apply addition proparty of equality: Add 4 to each side.

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$\"\"$

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$\"\"$ (Apply Additive inverse proparty: $\"\"$ )

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

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Apply multiplication proparty of equality: Multiply each side by 4.

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$\"\"$

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$\"\"$ (Cancel common terms)

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

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$\"\"$

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Check:

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To check the solution substitute 15 for x 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.

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$\"\"$

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The value of $\"\"$ .