What is the value of x in the following equation 1/5x=5^8 a)-8 b) 8 c)40 d)-40

The correct question is
What is the value of x in the following equation (1/5)^x=5^8 

Applying logarithms both members
log(1/5)^x=log(5^8) 
x*log(1/5)=8*log(5)
x=8*log(5)/log(1/5)

we know that
log (1/5)> log (1)-log (5)> 0-log (5)> -log (5)
so
x=8*log(5)/-log (5)> x=-8

the answer is
-8

A. 40

Step-by-step explanation: