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

\

The equation is $\"\"$ .

\

$\"\"$ (Distribute 6)

\

$\"\"$ (Multiply: $\"\"$ )

\

$\"\"$ (Subtract 3x from each side)

\

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

\

$\"\"$ (Apply commutative property of addition: $\"\"$ )

\

$\"\"$ (Subtract: $\"\"$ ) $\"\"$ $\"\"$ (Subtract 18 from each side)

\

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

\

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

\

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

\

$\"\"$ (Cancel common terms)

\

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

\

$\"\"$

\

Check:

\

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

\

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

\

$\"\"$ (Multiply: $\"\"$ )

\

$\"\"$

\

The value of $\"\"$ .