$\"\"$

The expression is $\"\"$ .

The logarithmic values are $\"\"$ and $\"\"$ .

Simplify the expression.

$\"\"$ (Original expression)

$\"\"$ (Quotient property of logarithm: $\"\"$ )

$\"\"$ (Substitute: $\"\"$ and $\"\"$ )

$\"\"$ (Subtraction)

$\"\"$ .

Therefore, approximate value of the expression is $\"\"$ .

$\"\"$

The approximate value of the expression is $\"\"$ .