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

The equation is $\"\"$ .

According to additon property of equality:Add 9 to each side.

$\"\"$

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

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

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

Check:

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

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

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

The equation is true. $\"\"$

The value of $\"\"$ .