$\"\"$

The proportion is $\"\"$ .

Apply cross product property: If $\"\"$ , then ad = bc.

$\"\"$ (Cross products)

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

Apply division property of equality: Divide each side by 28.

$\"\"$

$\"\"$ (Cancel common terms)

u = 5 (Divide: $\"\"$ ) $\"\"$

The value of u = 5.