$\"\"$

The expression is $\"\"$ .

$\"\"$ (Write the expression)

$\"\"$ (Subtract 12 from each side)

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

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

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

The solution is $\"\"$ . $\"\"$

Check:

Substitute $\"\"$ in the expression.

$\"\"$ (Write the expression)

$\"\"$ (Substitute $\"\"$ )

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

The solution was checked. $\"\"$

The solution is $\"\"$ .