$\"\"$

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

$\"\"$

$\"\"$ (Subtract 2.5 from each side)

Apply Additive inverse proparty: $\"\"$ .

$\"\"$

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

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

$\"\"$

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

$\"\"$ (Cancel common terms) $\"\"$

$\"\"$

$\"\"$ .