$\"\"$

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The equation is $\"\"$

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

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$\"\"$ (Subtract 5c from both sides)

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According to Commutative property of Addition: a + b = b + a.

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$\"\"$

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

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

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

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

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

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$\"\"$

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$\"\"$ (Divide both sides by 15)

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$\"\"$ (Cancel common terms)

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

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$\"\"$

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Verify the solution:

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

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$\"\"$

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

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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 $\"\"$ .