[tex]\it B = \left[\dfrac{1}{2}\left(\dfrac{1}{3} +\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{9}\right)\right]^4 = \left(\dfrac{1}{2}\right)^4 \left(\dfrac{1}{3} +\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{9}\right)^4 =
\\\;\\ \\\;\\
=\dfrac{1}{2^4}\cdot A [/tex]
[tex]\it \dfrac{A}{B} = \dfrac{A}{\dfrac{1}{2^4}\cdot A} = \dfrac{1}{\dfrac{1}{2^4}}=1:\dfrac{1}{2^4} =1\cdot\dfrac{2^4}{1} = 2^4[/tex]
