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

The expression is $\"\"$ .

According to subtraction property of equality: Subtract 9 from each side.

$\"\"$

$\"\"$ (Apply commutative property of addition: a + b = b + a)

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

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

Check:

Check the solution by substituting $\"\"$ in the original equation.

$\"\"$

$\"\"$ (Subtract: 9 – 3 = 6) $\"\"$

The value of $\"\"$ .