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

The equation is $\"\"$ .

Apply addition property of equality: Add 6.7 to each side.

$\"\"$

$\"\"$ (Apply additive inverse property: $\"\"$ )

$\"\"$ (Apply additive identity property: $\"\"$ )

$\"\"$ (Add: 5.8 + 6.7 = 12.5) $\"\"$

Check:

To check, substitute $\"\"$ in original equation.

$\"\"$

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

The value of $\"\"$ .