$\"\"$

The expression is $\"\"$ .

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

Simplify the expression.

$\"\"$ (Original expression)

$\"\"$ (Logarithm quotient property: $\"\"$ )

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

$\"\"$ (Logarithm product property: $\"\"$ )

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

$\"\"$ (Addition)

$\"\"$ .

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

$\"\"$

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