Use the 'change of base' formula:



on each of the first three terms on the left, using  as the 


 
Now we can evaluate those three denominators by using the definition of
logarithm:

    is equivalent to 

For , we set it equal to the unknown "y":



Then it is equivalent to  or , so ,
therefore   

------

For , we set it equal to the unknown "z":



Then it is equivalent to  or , so ,
therefore  

------

For , we set it equal to the unknown "w":



Then it is equivalent to  or , so ,
therefore  

------

Substitute these for the first three terms of:





Clear of fractions by multiplying every term by LCD = 12









Divide both sides by 25





Now use the definition of logarithm again to rewrite
that as



Find that on a TI calculator by typing 

2^(72/25)

then pressing ENTER

  

Edwin