SOLUTION: if 21 = -20loga , then the value of a

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Question 781466: if 21 = -20loga , then the value of a
Answer by tommyt3rd(5050) About Me  (Show Source):
You can put this solution on YOUR website!
21 = -20loga
log a = -21/20
10^log a = 10^(-21/20)
a=10^(-21/20)