$\"\"$

The identity equation is $\"\"$ .

Group like terms and apply distributive property: $\"\"$ .

$\"\"$ .

Comparison coefficient of x - term and constant terms on both sides of equation.

$\"\"$ .

To find the value of a, solve either equation 1 or equation 2.

Solve the equation 2: $\"\"$ .

Divide each side by negative 7.

$\"\"$

Cancel common terms.

$\"\"$ . $\"\"$

The value of $\"\"$ .