Find $r$ such that $\log_{81} (2r-1) = -1/2$.
Question:
Find $r$ such that $\log_{81} (2r-1) = -1/2$.
Answer:
Let's think step by step.

user
\frac{5}{9}
Find $r$ such that $\log_{81} (2r-1) = -1/2$.
train