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

The expression is $\"\"$ .

According to addition property of equality: Add 7 to each side.

$\"\"$

$\"\"$ (Additive inverse property: $\"\"$ )

$\"\"$ (Additive identity property: $\"\"$ )

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

The value of expression is $\"\"$ .