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

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The equation is $\"\"$ .

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According to subtraction property of equality: if $\"\"$ , then $\"\"$ .

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$\"\"$ (Subtract 4z from each side)

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$\"\"$ (Additive inverse property: $\"\"$ )

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$\"\"$ (Additive identity property: $\"\"$ )

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

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$\"\"$

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$\"\"$ (Subtract 5 from each side)

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$\"\"$ (Commutative property: a + b = b + a)

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$\"\"$ (Additive inverse property: $\"\"$ )

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$\"\"$ (Additive identity property: $\"\"$ ) \ \

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

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$\"\"$

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

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$\"\"$ (Cancel common terms)

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$\"\"$ \ \ (Divide: $\"\"$ )

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$\"\"$ \ \

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Check:

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

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Compare the values, the equation is true.

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$\"\"$

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The value of $\"\"$ .

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