$\"\"$

(a)

The expression is $\"\"$ .

Change of base formula for common logarithm : $\"\"$ .

$\"\"$ .

Thus, $\"\"$ . $\"\"$

(b)

The expression is $\"\"$ .

Change of base formula for natural logarithm : $\"\"$ .

$\"\"$ .

Thus, $\"\"$ . $\"\"$

(a) $\"\"$ .

(b) $\"\"$ .