If (1/2)^25 (1/81)^k = 1/18^25, then k = Choose the correct choice from the following answers
A) 8  B) 12.5  C) 16  D) 24  E) 36
I'm going to focus on denominator only..   (2^25) . ((3^4)^k = 18^25   (2^25) . ((3^4k) = (2. 3^2)^25   (2^25) . ((3^4k) = (2^25) . (3^2)^25   hence   4k = 50   k = 12,5   answer 12.5   I hope it's quite clear
<result>B</result>
If (1/2)^25 (1/81)^k = 1/18^25, then k =