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The sum of a number and its additive inverse is zero.

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$\"\"$ (Subtract 2.5 on both sides)

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

$\"\"$ (Apply Additive identity proparty: a + 0 = a $\"\"$

The product of a number and its multiplicative inverse is one.

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

$\"\"$ (Cancel common factors) $\"\"$

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