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

The equation is $\"\"$ .

According to subtraction property of equality if a = b then $\"\"$

$\"\"$ (Subtract 9 from each side)

$\"\"$ (Commutative property of addition: $\"\"$ )

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

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

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

Check:

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

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

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

The equality is true. $\"\"$

The equality solution is $\"\"$ .