$\"\"$

The formula of slope is $\"\"$ .

The line 1 passes through the points $\"\"$ .

Substitute the values of $\"\"$ in the above formula.

$\"\"$ .

The line 2 passes through the points $\"\"$ .

Substitute the values of $\"\"$ in the above formula.

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

If two lines are parallel then their slopes are equal.

Therefore $\"\"$ .

$\"\"$

Apply cross products property: If $\"\"$ then $\"\"$ .

$\"\"$

Add 2 to each side.

$\"\"$

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

The value of $\"\"$ .