$\"\"$

The expression is $\"\"$

$\"\"$ (Replace b with 12 in original expression)

$\"\"$ (Rewrite the expression as division problem) $\"\"$

By the order of operations (PEMDAS):

First evaluate the expression within the parenthesis.

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

Next operation is division.

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

The value of the expression is 3.