$\"\"$

The equation is $\"\"$ .

$\"\"$ (Add 7x to each side)

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

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

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

$\"\"$ (Multiply each side by 2)

$\"\"$ (Cancel common terms)

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

The value of $\"\"$ .