$\"\"$

The equation is $\"\"$ .

Apply addition property of equality: If a = b then a + c = b + c.

$\"\"$ (Subtract 7 from each side)

Apply commutative property of addition: a + b = b + a.

$\"\"$

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

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

$\"\"$

Apply division property of equality: If a = b then $\"\"$ .

$\"\"$ (Divide each side by 3)

$\"\"$ (Cancel common terms)

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

The value of $\"\"$ .